Every detail of Dr David Kelly’s tragic death on Harrowdown Hill near Longworth in 2003 has been raked over by the media, lone investigators, and conspiracy theorists in the hope of unearthing some crucial clue that could link a very solitary death to a geo-political crisis.

The weapons inspector had been outed as the source for BBC journalist Andrew Gilligan’s report which alleged the Government “probably knew” that a key claim over Saddam Hussein’s weapons capability was false before it was published.

His name thrust into the open, and on July 15 and 16, Dr Kelly was grilled intensively by two parliamentary committees. His wife said it left him “tired and subdued”.

The next day, he went for a walk near his house in Southmoor, and never returned.

After a police search, his body was found slumped against a tree.

He had apparently swallowed painkillers and cut his wrist with a pruning knife.

But with no full inquest ever heard at Oxfordshire Coroner’s Court, a death certificate signed off before the end of the inquiry into Dr Kelly’s death, and evidence sealed from the public gaze for 70 years, there has plenty of fuel for those set on tearing apart the official version of events.

They claim Lord Hutton’s inquiry into Dr Kelly’s death fell far short of an inquest: witnesses were not adequately cross-examined, discrepancies not investigated, and versions of events were accepted without being tested.

Only in December last year, was the post mortem examination – which confirms that Dr Kelly died as a result of incised wounds to his left wrist – released to the public.

Officially, Attorney General Dominic Grieve has yet to decide whether to order an inquest into Dr Kelly’s death, but Prime Minister David Cameron has already told MPs that he does not think it is “necessary”.

But the clamour for a fresh investigation is not going away.

Dr Kelly left no suicide note and had arranged to meet his daughter on the last day he was seen alive.

Others have alleged he was too weak to cut his own wrist, and point out no fingerprints were found on the knife found alongside him. Just one witness saw him on his walk between his home in Southmoor and Harrowdown Hill.

Dr Andrew Watt, a clinical pharmacologist who runs an investigative blog on the death, said: “Having carefully looked at the totality of evidence my view is that David Kelly was murdered.

“When the evidence is examined carefully the suicide hypothesis crumbles.”

Dr Watt, who calls himself a scientist rather than a conspiracy theorist, said Dr Kelly had no motive to kill himself, and has backed calls for an inquest.

He added: “The medical evidence is that David Kelly died on his back. Dead bodies do not sit themselves up.

“In addition, there are technical issues relating to the knife and the wounds on the left wrist described at postmortem which lead me to conclude that the wounds were made by a different knife and that the wounds were not self-inflicted.”

Oxford University conspiracy theory expert Dr Stephen Clarke said people could have “unrealistic expectations” that all available evidence should line up neatly in order to provide a clear version of events. He said the internet had put more conspiracy theorists in touch with each other.

He said: “As more and more evidence comes in, you ought to be able to abandon a theory, but unfortunately people do not.

“Many theories involve cover-ups, and any evidence against them can be explained away as a cover-up.”

Thames Valley Police have been reluctant over the years to be drawn into the theories, relying often on a stock quote that all investigative material was available to Hutton.

THE BLOOD Witnesses have had different recollections about the position Dr Kelly’s body was found in and the amount of blood around it.

Two Oxfordshire paramedics and a detective who went to the scene said they did not see much blood – seemingly incompatible with the wrist injury given as the primary cause of his death in the Hutton Report.

Conspiracy theorists have suggested that Dr Kelly’s body had been moved to Harrowdown Hill after his death, or that slashing his wrist was not the cause of death.

But Dr Nicholas Hunt’s post mortem, published last year, recorded “heavy bloodstaining” over the left arm, the knife, Dr Kelly’s clothes and the surrounding area.

FINGERPRINTS Freedom of Information requests have revealed a lack of fingerprints on the personal items found alongside Dr Kelly’s body.

No fingerprints were found on his knife, pill packets, water bottle, glasses, mobile phone or watch, but this was not revealed to the Hutton Inquiry.

Others have suggested an old injury had left Dr Kelly too weak to cut his own wrists, and that he had a medical condition that made it almost impossible to swallow pills.

THE POLICE HELICOPTER On the day Dr Kelly’s body was found, a helicopter hired by Thames Valley Police landed near Harrowdown Hill for five minutes.

Exact details of who was on board have not been released by the police. Conspiracy theorists have questioned whether it was used to deposit something or someone at the scene, or to remove something from the site.

Police have subsequently told the Oxford Mail the helicopter had been taking video footage of the scene from the air and the landing was to hand over that film. They say only helicopter staff were on board.

COMMUNICATIONS MAST On the evening that Dr Kelly went missing, police arrived with communications equipment to co-ordinate the search.

MP Norman Baker, who has written a book about Dr Kelly’s death, says one communications mast was 110ft-tall, saying the area is a black spot for radio communications.

But Mr Baker has suggested the equipment would be far more than what was needed to co-ordinate a police search, and could instead have been used to keep Prime Minister Tony Blair informed of events on his flight between Washington and Tokyo.

THE THIRD MAN At the Hutton Inquiry, Thames Valley Police officer DC Graham Coe said only one other man, DC Colin Shields, was with him at the scene in the period after the body’s discovery.

Other witnesses later revealed there were three men, with DC Coe later telling a national newspaper that he was a trainee police officer.

Conspiracy theorists ask: who was this third man, and why was his presence not confirmed to Lord Hutton?

Other unidentified figures include a group of boat users stationed near Dr Kelly on the day his body was found.