Medical records which would shed light on the death of government scientist David Kelly will be kept secret for 70 years, it emerged yesterday.

The unprecedented move has been ordered by Lord Hutton, who chaired the inquiry which controversially concluded that the mysterious death was suicide.

It means vital evidence, including the results of Dr Kelly's post-mortem examination - which have never been made public - will remain under wraps until 2073, by which time anyone involved in the case will almost certainly be dead.

Whistle-blower: Dr Kelly died after casting doubt on Government claims about Saddam's weapons

The body of 59-year- old UN weapons inspector Dr Kelly was found in July 2003 in woods near his Oxfordshire home. Days earlier he had been revealed as the source of a BBC story claiming evidence against Iraq had been 'sexed up' to justify invasion.

No coroner's inquest has been held into the death.

Last night, Dr Michael Powers QC, a doctor campaigning to overturn Lord Hutton's findings, told the Daily Mail: 'I cannot understand why this extraordinary move has been taken.

'It does give rise, perhaps unnecessarily, to a suspicion that information relevant to these circumstances was kept out of the public eye.

'The surprising thing to me is that if this report supports the conclusion that the medical cause of death was suicide, why does it need to be locked up for 70 years?

'If on the other hand it doesn't, and supports other means of death, then why wasn't this evidence investigated by the Hutton inquiry?

The move will stoke fresh speculation about the true circumstances of Dr Kelly's death.

'It is very difficult to understand what is so precious and important about the medical reports and tests which stops any of us having sight of this until everyone with any knowledge or interest in the case is dead.'

Liberal Democrat MP Norman Baker, who has also cast doubt on the official version of events, said: 'It is astonishing this is the first we've known about this decision by Lord Hutton and even more astonishing he should have seen fit to hide this material away.'

Lord Hutton's restrictions - which were imposed immediately after his inquiry in 2004 - came to light in a letter from Oxfordshire County Council to a group of 13 doctors, led by Dr Powers, challenging the Hutton verdict.

It revealed that an order had been imposed which placed a 30-year ban the release of records that were provided to the inquiry but not used in evidence - believed to be witness statements.

In addition, the letter said that medical reports and photographs of Dr Kelly's body would remain classified information for 70 years after his death.

Nicholas Gardiner, chief coroner for Oxfordshire, said the restriction may have been used to protect Dr Kelly's children.

Dr David Halpin, another of the group of 13 doctors, said last night: 'I am shocked but not surprised by this.

'It fits in with the subversion of due process we have seen for six years. It is extraordinary.'

Both Dr Halpin and Dr Powers said they would like to see the Chilcot panel ask why the ban was imposed.

Dr Powers said: 'We would like to know the part government ministers played in the decision.'

The Ministry of Justice has not explained the legal basis for Lord Hutton's order.

A spokesman said: 'Any decision made by Lord Hutton was entirely a matter for him.'

Lord Hutton was unavailable for comment.