Lord Hutton has responded to reports that a 70-year gagging order he imposed on records and photos relating to the death of the government scientist Dr David Kelly could be challenged by stating that the documents could be revealed to doctors.

In a U-turn, Hutton said the information could be released to five doctors who are seeking to reopen the inquest into Kelly's death.

"I requested that the postmortem report should not be disclosed for 70 years as I was concerned that the publication of that report would cause [Kelly's] daughters and his wife further and unnecessary distress," Hutton said.

"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."

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 that could be fired within 45 minutes. An inquest was suspended by Lord Falconer, then lord chancellor, before the Hutton inquiry, and then not resumed after Hutton's report in 2004 concluded that Kelly killed himself by cutting an artery in his wrist.

News that the secrecy ruling would be lifted came after the Guardian reported that five doctors were considering a legal challenge to the decision to keep the material secret. "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 postmortem) reports and photographs be closed for 70 years," the doctors were told in a letter.

The doctors' request came in response to continuing questions about the Hutton inquiry's finding that Kelly killed himself. "We do not suggest his suicide was impossible, but it was so improbable as to demand a much more detailed investigation of what happened," said Michael Powers QC, who has been working with the doctors who requested the material from the coroner.

"A coroner would not have concluded Kelly's death was a suicide unless it was proved beyond reasonable doubt. From that point of view, and from a lawyer's and a medical professional's point of view, there is a justifiable concern that there was not sufficient inquiry into those circumstances," he added.

Hutton's ruling was not made public at the time. Lawyers said they were unsure of the legal basis for his decision to keep the material secret and to choose a period of 70 years.