The aircraft only remained on the ground for five minutes before leaving, suggesting it either deposited or collected somebody or something.
Details from its flight log, released under the Freedom of Information Act, show that the helicopter – hired by Thames Valley police – landed at Harrowdown Hill in Oxfordshire at 10.55am on July 18, 2003, 90 minutes after the body was discovered by volunteer search teams.
Significantly, the flight log has been heavily redacted, making it impossible to know who was on board or what its exact purpose was.
The flight was not mentioned in oral evidence at the Hutton Inquiry, set up by Tony Blair to investigate Dr Kelly’s death.
Dr Andrew Watt, who has previously raised questions about the suicide finding reached by Lord Hutton, has written to Attorney General Dominic Grieve drawing his attention to the flight.
Dr Watt, a clinical pharmacologist, said: ‘If the purpose of the helicopter flight was innocent, one has to ask why it was kept secret.’
The riddle joins the growing list of unanswered questions about the circumstances of the government weapons inspector’s final moments.
It emerges in the same week that Tony Blair and Alastair Campbell were accused of lying to the Chilcot Inquiry into the lead-up to the Iraq war.
The Mail reported yesterday how declassified documents from the inquiry revealed a spy chief disputed Campbell’s claim that the dossier was ‘not the case for war’.
A senior diplomat also accused the former prime minister of distorting expert reports about the post-war chaos.
Dr Kelly is said to have killed himself in woods near his home after being named as the prime source of a BBC report accusing the Labour government of lying to take Britain into war in Iraq.
Uniquely for a suspicious death, no coroner’s inquest has been held. Instead, the Hutton Inquiry found he committed suicide by swallowing painkillers and cutting his wrist with a blunt knife.
Dr Kelly left no suicide note and had arranged to meet his daughter on July 17, 2003, the day he was last seen alive.
He had also made plans to see friends the following week and, on the morning of his death, booked a return ticket to Iraq in connection with his work.
The latest disclosure comes as Attorney General Mr Grieve prepares to announce whether there will be an inquest into Dr Kelly’s death. He has waited almost a year to reach a decision.
In opposition, Mr Grieve told at least two fellow MPs privately that he had misgivings about the Kelly affair.
Last June, after the Coalition was formed, he asked anyone with new information about Dr Kelly’s death to send it to him and over the last nine months has been informed of several pieces of material evidence which were never raised at the Hutton Inquiry.
Crucially, a non-statutory public inquiry such as Hutton has none of the powers of a coroner’s inquest.
Witnesses, including Mr Blair and Mr Campbell, did not swear an oath before giving evidence.
A group of doctors has begun a legal action to try to secure an inquest.
Papers submitted through their lawyers Leigh Day & Co say the suicide finding is medically implausible and should be investigated fully by an experienced coroner, not a judge.
The doctors have set up a fund to raise £25,000 for a judicial review in case Mr Grieve decides there is no case for an inquest.
Dr Michael Powers QC, representing the doctors, said: ‘Dominic Grieve has been sitting on a substantial amount of new evidence for a very long time.
‘In law, the case for a coroner’s inquest is unanswerable.’