POLICE who re-investigated the deaths of four army recruits at Deepcut barracks believed they were almost certainly murdered, it was revealed yesterday.

The Devon and Cornwall force - which reviewed the original, much-criticised investigation by Surrey police - concluded the probe "should have been treated only as murder".

The Surrey force had focused on "self-infliction or assisted suicide" as alternative explanations for the four mysterious deaths, all from shotgun wounds.

The revelation was contained in previously unpublished minutes of a Surrey police authority meeting .

Geoff Gray, the father of 17-year-old Private Geoff Gray, from Seaham, County Durham, who was one of the four victims, spoke of his fury that the recommendation had been ignored.

Mr Gray has always rejected the conclusion of a QC's independent review that his son almost certainly shot himself because of his "morbid state of mind".

Last night, he said: "This shows it should have been a murder inquiry, not some half-baked investigation looking at assisted suicide.

"My son was shot twice, above each eyebrow. How on earth could he have committed suicide? How many times have I got to say that there should be a public inquiry, held in the open by a judge?"

Mr Gray won support from Liberal Democrat MP Lembit Opik, who demanded the Government order the release of the full review carried out by Devon and Cornwall force.

Mr Opik said: "This minute is unambiguous."

Controversy has raged for years about the deaths at Deepcut of Pte Gray, Sean Benton, 20, James Collinson, 17, and Cheryl James, 18, between 1995 and 2002.

Geoff and Diane Gray have fought a long campaign to find out the truth, after it emerged their son was shot twice and it was reported that a figure was seen running away.

An inquest recorded an open verdict, but last year's review by human rights lawyer Nicholas Blake QC concluded there was no evidence that Pte Gray was either murdered or "bullied to death".

Mr Blake agreed the death was mysterious, but decided it was "even more perplexing" to believe another person had shot the trainee only to "disappear without leaving any evidential trace".

The verdict was a bitter blow to the Grays - as was armed forces minister Adam Ingram's insistence that it was time to "move on", without a public inquiry.

The Surrey Police minutes from November 17, 2005, released in response to a Freedom of Information request, were revealed at a Westminster press conference yesterday.

They read: "There was a fundamental disagreement between the forces on the approach adopted by Surrey Police and this had been referred to the service's professional advisers for clarification.

"Devon and Cornwall were of the view that the investigation should have been treated only as murder. Surrey Police had taken a broader approach to the investigation, including the possibility of murder, self-infliction or assisted suicide".

Last night, the Surrey force defended its procedures, insisting it was "already well documented" that there was a difference of opinion with Devon and Cornwall.

A spokesman said: "All of the issues raised today by Lembit Opik MP have already been well examined.

"Despite scrutiny by three recognised official bodies - the Blake Review, HM Coroner for Surrey and the Independent Police Complaints Commission - no significant issues have been found which would have affected the outcome of the investigation."