A sado-masochistic former training instructor from the controversial Deepcut army barracks was sentenced to four-and-a-half years in jail yesterday for a catalogue of sex attacks on young male soldiers.

Leslie Skinner, 46, took advantage of his apparent superiority to prey on four young men during the 1990s - three at Deepcut Barracks, in Surrey, and one, earlier, at Arnhem Barracks, in Aldershot.

Skinner, of Marton, near Gainsborough, Lincolnshire, had already been convicted of a sexual offence by a court martial.

Kingston Crown Court heard Skinner was convicted of indecently exposing himself to a 17-year-old boy by the court martial in Northern Ireland in 1996. He was reduced in rank to private as a result.

But rather than being discharged, he was sent to Deepcut, where he carried out the bulk of his attacks.

Judge Charles Tilling said: "For some reason best known to itself, the Army then placed you in a position where you were in contact with and had influence over young recruits.

"Far from heeding the warning that your reduction in rank should have given you, you proceeded to indecently assault another three young vulnerable soldiers.

"Those who enter the Army at that sort of age have and should expect to be able to have protection from this sort of behaviour."

Skinner, who is married with two young children, has been jailed for two years on one count of indecent assault and a further two-and-a-half years for a further four. He will also be placed on the sex offenders register.

Skinner had been due to stand trial at Kingston Crown Court last month on nine charges of indecent assault and one of male rape. But he changed his plea at the 11th hour and admitted five counts of indecent assault. The judge yesterday quashed the outstanding charges.

Skinner's activities came to light when one of his former victims, David Leaning, spoke about the abuse after watching a discussion on the BBC's Kilroy programme.

Four eventually came forward to tell police of assaults, ranging from one waking up to find Skinner performing a lewd act on him to others being made to take part in sado-masochistic sessions.

At Deepcut, where he was a training instructor, Skinner kept canes and a riding crop in his locker, which he used for sexual kicks. During one attack, Skinner used a Black and Decker Workmate.

Skinner has since been court-martialled for a further indecent assault and jailed for six months before being discharged from the Army.

Although there is no suggestion of a link between Skinner's activities and the deaths of four young recruits at the barracks, campaigners pointed out that the case highlighted concerns about the care of young soldiers at Deepcut.

Jim Collinson, whose son James, 17, was found dead at Deepcut in 2002, said: "There is definitely a wider matter at Deepcut. All the time that we have been carrying on our campaign for justice for the recruits, there have been more and more people coming forward, telling harrowing stories of bullying and threats. And now today we have had proof of sexual abuse of youngsters."

Diane Gray, whose son Geoff, of Seaham, County Durham, died at Deepcut in 2001, echoed Mr Collinson's sentiments.

She said: "It has been covered up. It shows that the Army knew what was going on the first time he did it in Northern Ireland.

"They knew what was going on and they allowed it to happen, they did nothing about it. They moved him straight to Deepcut where it was allowed to carry on."