David Kelly's body was found near his Oxfordshire home in 2003
Details of the post-mortem examination of government weapons inspector David Kelly should be seen by doctors seeking an inquest, Lord Hutton has said.
The peer confirmed he had requested a 70-year gagging order on the material at the conclusion of his inquiry into Dr Kelly's 2003 death.
But he said on Tuesday the purpose of the secrecy order had been to avoid causing distress to Dr Kelly's family.
He has written to ministers saying the report may be seen by the doctors.
Dr Kelly's body was found in woods close to his Oxfordshire home in 2003, shortly after it was revealed that he was the source of a BBC report casting doubt on the government's claim that Iraq had weapons of mass destruction capable of being fired within 45 minutes.
An inquest was suspended by then Lord Chancellor Lord Falconer, who ruled that Lord Hutton's inquiry could take its place.
Lord Hutton's report in 2004 concluded that Dr Kelly had killed himself by cutting an artery in his wrist.
But the finding has been challenged by doctors who claim that the weapons inspector's stated injuries were not serious enough.
One of them, former assistant coroner Michael Powers, raised concerns over the secrecy order after seeing a letter from the legal team of Oxfordshire County Council explaining the unusual restrictions placed by Lord Hutton on material relating to his inquiry.
The letter stated: "Lord Hutton made a request for the records provided to the inquiry, not produced in evidence, to be closed for 30 years, and that medical (including post-mortem) reports and photographs be closed for 70 years."
On Tuesday, Lord Hutton released a statement explaining his decision and revealing that he had written to the Ministry of Justice.
In it, he said: "At the conclusion of my inquiry into the death of Dr David Kelly, I requested that the post-mortem report relating to his death should not be disclosed for 70 years as I was concerned that the publication of that report in newspapers, books and magazines would cause his daughters and his wife further and unnecessary distress.
"Much of the material in the post-mortem report had been given in oral evidence in public at the inquiry and substantial parts of that evidence had been set out in my report.
"However, I consider that the disclosure of the report to doctors and their legal advisers for the purposes of legal proceedings would not undermine the protection which I wished to give to Dr Kelly's family, provided that conditions were imposed restricting the use and publication of the report to such proceedings, and I have written to the Ministry of Justice to this effect."
Liberal Democrat MP Norman Baker, who has conducted his own inquiries into Dr Kelly's death, said: "It's astonishing and unheard-of for material of this nature to be hidden away for any length of time, let alone 70 years.
"Coroners' inquests are held in public. Lord Hutton's inquiry was unique in its format and unique in requesting restrictions of this nature.
"His statement today undermines the validity of his own inquiry and gives further justification to the case being made by many for a proper inquest to be held into this most public of deaths."