COPS last night refused to comment on reports that a helicopter mysteriously landed at the scene of weapons expert Dr David Kelly's death shortly after his body was found.
Details released under the Freedom of Information Act show the aircraft stayed on the ground for five minutes before leaving.
Dr Andrew Watt, who has raised doubts about the circumstances around Dr Kelly's death, said: "If the purpose of the helicopter flight was innocent, one has to ask why it was kept secret."
Kelly's death came soon after he was named as the source of reports questioning the Government's "dodgy" dossier arguing the case for war in Iraq.
The Hutton Inquiry found the Government weapons inspector committed suicide, but paramedics, doctors and MPs have questioned the official account of his death.
On 7 July 1947 a rancher in New Mexico reported the discovery of a strange flying saucer that had crash landed in the desert 40 miles north of the small Air Force town of Roswell.
With its strange markings and unusual design, the find soon sparked a furious debate about where the bizarre craft could have come from.
The summer of 1947 had seen dozens of UFO sightings over Roswell.
Locals reported blinking lights, hovering discs and oddly-shaped aircraft in the clear night skies.
So when the Air Force issued a press release saying that a flying disc had been found, the rumour mill went into overdrive.
To those convinced that we are not alone in the universe, Roswell was the defining moment that saw years of UFO sightings and alien encounters backed up with cold, hard evidence.
But the UFO theory was quickly dispelled by military officials, who claimed the object they had recovered was a humble weather balloon, and for more than 30 years the eyes of the world turned away from the New Mexico desert.
Then, in 1980, retired Major Jesse Marcel, who had been involved in the recovery of the craft, told the National Enquirer that the military had covered-up the discovery of an alien spaceship at Roswell.
Since that interview the incident has gained legendary status in the conspiracy community,
For millions across the globe, it is the strongest proof yet that the US government has concealed the existence of aliens for more than 60 years. The American military continues to refute the claims of UFO enthusiasts, and intelligence chiefs have stuck to their "weather balloon" story since 1947.
So have we all been duped by a government cover-up to convince the public that little green men and flying saucers are make believe, or is Roswell just another UFO hoax?
Martin Bormann was among the most sinister and feared members of the Nazi high command.
A trusted member of Hitler's inner circle, and head of the chancellery, Bormann was the FÃÅhrer's right hand man.
He was regarded by the Nazis as a true believer, a zealot to the fascist cause, so completely committed to the Third Reich's odious aims of racial purification that he was above suspicion.
But as the Nazi regime crumbled, and the Soviet troops stormed Berlin, things rapidly changed for this pragmatic bureaucrat. It is suggested that Bormann may not be the dedicated, boot-licking Hitler devotee that he made himself out to be.
Conspiracy theorists believe Bormann was in fact a Russian spy, a murky contact known to Stalin's intelligence chiefs as "Werther".
There is little doubt that a high-ranking German had been turned by their communist foes, but Bormann was not just any member of the high command, he was the personification of the Nazi stooge, Hitler's personal secretary, and a fearsome ideologue.
If the Russians did turn Bormann, it must be regarded as the espionage coup of the century.
But could a rabid, FÃÅhrer-worshipping Nazi like Bormann really have fed information to Hitler's most hated foe, and if he did, how on earth did he manage to get away with it?
This theory has it all, little green men, a Cold War backdrop, nuclear missiles, and retired army men going public with their 'proof' that humans are not alone in the universe.
In a nutshell, a group of former US troops will present their case later today that extraterrestrial beings frequently visit the earth and tamper with our nuclear weapons in both the UK and US.
Captain Robert Salas and his five ex-military cohorts say they have cast iron evidence that aliens have been tampering with minutemen missiles, and that UFOs have caused major blackouts that threatened to spark a nuclear holocaust at the height of the Cold War.
You can read more about Salas' claims here.
This could be the long-awaited proof of alien existence that X Files enthusiasts have been holding their breath for.
Or it could be a tall tale born out of a small grain of truth - harking back to a time when experimental Russian crafts were being developed to interrupt signals and communications at allied nuclear sites.
The question is - do you want to believe?
After a week of speculation the Attorney General has refused to release secret documents about the death of Iraqi weapons inspector Dr David Kelly.
This decision comes after leading medical experts, Dr Kelly's family and even members of the ruling coalition government, called for a full inquest into his alleged "suicide".
The weight of medical evidence against the official version of his death is staggering, and conspiracy theories abound over the possible involvement of the government, rogue MI6 agents or even Iraqi death squads.
Here is our original detailed look at the conspiracy theory surrounding Dr Kelly's death, make up your own mind as to where the truth lies.....
In 1999 Russia stood at a crossroads.
The newly capitalist nation was beset by internal unrest, torn apart by rivalries between billionaire oligarchs redrawing the map for their own commercial interests and constantly under threat of terrorism from Chechen rebels seeking an independent homeland.
Into this chaotic scene stepped Vladimir Putin, now familiar as the shirtless, hunting, fishing, Russian ironman who would rule his country like a modern day Tsar.
Back then he was a determined, ambitious, former commander in the FSB, the new secret service fast gaining a reputation as the KGB of the 21st century.
Putin's bid for power was based on his tough stance on Chechnya, his no-nonsense approach to terrorism, and his promise to rebuild a strong Russia from the ashes of its post-USSR breakdown.
As President Boris Yeltsin was facing the boot over corruption allegations, a string of apartment bombings rocked the cities of Moscow, Buynaksk, and Volgodonsk - killing 300 people and injuring over a thousand.
The attacks would be the catalyst for a second war against the Chechen rebels, but more than that they precipitated a massive shift in the base of power, and coincided the emergence of the previously unheralded Putin as Russia's pre-eminent political force. Within a year Putin had amassed a huge base of voters, and was popularly elected President for his handling of the war.
But the story did not end there.
With the Putin regime firmly in place, dissident former spies, including Alexander Litvinenko, who died in agony from polonium poisoning in London in 2006, came forward to warn that the bombings were a covert FSB operation.
Litvinenko and others suggested that the secret service had carried out the attacks as part of a false flag conspiracy to paint the Chechen rebels as the culprits and launch the war which would bring Putin to power.
As the whistle blowers began to be silenced, the conspiracy theory only grew stronger.
The question is, could the FSB pull this off, and just how far up the chain of power does this theory go?
From Napoleon to Hitler, some of the most powerful dictators in history have sought and obtained the Lance of Longinus - also known as the Spear of Destiny.
Said to be the holy sword which was used to slice open Jesus Christ at his Crucifixion, the blade is one of the most precious archeological pieces in the world.
Currently believed to be in the possession of an Austrian museum, myths and rumours have circulated for generations about the spear's supposed mystical powers.
Legend has it that the tip of the spear could allow its owner to rule the world, and the Fuhrer certainly believed in its power, enough to make it his number one priority when invading Austria.
Hitler is understood to have carried the artefact with him in the belief that it could make his Nazi army the rulers of the planet for all eternity.
Where the spear came from, whether it is the blade that pierced the skin of Christ, and what powers it truly possesses are all subject to endless conspiracy theories and folk stories.
Questions still surround the relic.
Could the Spear of Destiny really be the reason Hitler invaded Austria?
Will it be safe in its new location should another maniac come searching for it?
But the most important question remains - How much of this tale is myth, and how much is fact?
From allegedly crooked referees to absolutely crocked players, the FIFA World Cup has had more than its fair share of controversy both on and off the pitch.
Over the years we have watched as the Hand of God robbed England of glory, the diving antics of the Germans went unpunished and penalty heartbreak hit the Three Lions over and over again.
In honour of the start of this year's tournament in South Africa, The Grassy Knoll is taking a look at 5 of the World Cup conspiracy theories that have consumed fans over the years.
For just ÃÂ£800,000 you can now buy yourself a piece of American folklore history.
Because despite what the real estate reports might say, 108 Ocean Avenue in the Long Island, New York, suburb of Amityville, is no ordinary seafront property.
It is in fact the original 112 Ocean Avenue, scene of the most infamous haunting in history, and subject of more books, films and general hysteria than any ghost story ever told.
The tale starts on a chilly November night in 1974 when Ronald DeFeo Jr wakes in the middle of the night and calmly shoots each member of his sleeping family between the eyes.
Confessing to cops after originally concocting a tale involving a mafia hit, he tells officers that he "just couldn't stop" killing and later mounts a defence of insanity based on hearing voices in his head instructing him to slaughter Ronald DeFeo Sr. his mother Louise DeFeo and his four siblings Dawn, 18, Allison, 13, Marc, 12, and John Matthew, 9.
This tragic and brutal murder spree ended in the caging of Ronald DeFeo Jr for six consecutive life terms, and to this day the killer remains in a maximum security lock-up in upstate New York.
But what took place in the year after the slaying of the DeFeos would go on to shock the nation and create a global paranormal phenomena as Kathy and George Lutz, who brought the dream Ocean Avenue property after the killings, claimed they were forced from their home after just 28 days by a demonic spirit which threatened their lives.
In the years that have followed their story has become a movie sensation, a best selling novel and a focus for the paranormal experts who believe this middle class New York couple were truly plagued by spirits from another dimension.
But a more sinister conspiracy has been identified by sceptics.
With millions of dollars in their back pockets, the Lutzes have done well from their terrifying four weeks on Ocean Avenue, and the conspiracy theory runs that this was a very well thought out hoax, aimed at paying off their dream home and ensuring their financial future.
The Lutz family have strenuously denied these claims, but the question still remains, was the Amityville horror story a haunting or a hoax?
Every year the world's most powerful men and women join together to drink cocktails, smoke cigars, and - possibly - control the fate of the entire planet.
Founded in 1954 the Bilderberg group is one of the most infamous and shadowy organisations on earth.
Notable attendees include Presidents and Prime Ministers, captains of industry, media magnates and banking plutocrats.
To most, this group is just another talking shop, a collection of the great and good gathering together to discuss boosting profits.
But many conspiracy theorists fear that these men represent a powerful cabal of dastardly puppet masters, making war, deciding the fate of the public and controlling our lives through their all encompassing influence over the world economy.
Of all the secret society theories, this is the most well developed, not least because Bilderberg members have admitted to attending meetings and have been photographed coming in and out of the swanky hotels where these annual get-togethers are held.
However, the meeting locations are always a closely guarded secret, and there is a strict no press policy.
Maybe they are just publicity shy, or maybe they have something to hide.
Whatever their justifications for the meeting the Bilderbergers are facing some pretty tough questions.
Exactly what are they discussing, how far does their influence reach and is the fate of the world being sealed behind closed doors by a powerful elite answerable to no-one?