THE families of the Deepcut Army base victims demanded answers last night after claims that security services are watching their every move.

Reports at the weekend suggested that MI5 officers were working with the Army's Special Investigations Branch to monitor the families' push for a public inquiry into mysterious deaths at the Surrey barracks.

Private Geoff Gray, 17, of Seaham, County Durham, was one of four soldiers to be found dead with gunshot wounds between 1995 and 2001.

And Pte Gray's father, Geoff, revealed last night that police were due to sweep his family home for possible bugging devices this week. It followed a sweep of the Scotland home of Jim and Yvonne Collinson, whose son James also died at Deepcut, on Friday.

Surrey officers are said to have initiated the move after hearing noises on phone lines during conversations with the family.

Mr Gray said: "We have been having all sorts of problems with the phones. Surrey Police refused to talk to me on my phone while I was in the house - they said I would have to go outside," he said.

"Some department or other is getting twitchy, but all we want at the end of the day is the truth, so I don't know why they are doing this. I have got the National Crime Squad coming to sweep our house for bugs."

New laws have recently given the security service and chief constables the power to order phone taps.

Independent investigator Frank Swann, a forensic and ballistics expert, has launched a probe into the deaths of Pte Gray, Pte Collinson, Pte Sean Benton and Pte Cheryl James.

Their families refuse to accept that all four deliberately killed themselves using their own rifles, and have accused the Army of a cover-up.

They are also pushing for their case to be heard during an adjournment debate on non-combat Army deaths, in the House of Commons on February 5.

Surrey Police declined to comment on the development last night.