PRISON officers at Winchester prison are to be issued with special safety' knives in an attempt to reduce the number of inmates committing suicide.

The knives will be carried by all officers on cell patrol and will be used to cut down any prisoners trying to hang themselves.

Ombudsman The decision to ask officers to carry the knives has come from the UK's prison ombudsman, Stephen Shaw, who actually recommended the move to the Home Office 17 times before bosses there took notice.

Mr Shaw made his decision after spending 18 months in office investigating prison deaths and finding that 90 per cent of inmates who attempted suicide tried to hang themselves.

The chances of surviving a hanging are far higher if the prisoner is cut down as soon as someone finds them, but if officers don't carry knives, time is wasted fetching one before a prisoner can be released.

The knives, called cut-down tools', are hook-shaped and have their blade encased in a protective guard so it is almost impossible to slash or stab someone, but still possible to use the knife to cut through a rope.

Mr Shaw said it had been regarded as best practice for the past four years for prison officers to carry a knife, particularly on night patrols, but added that in many cases knives were kept in offices.

He said: "A matter of seconds can make a difference when somebody loses consciousness in terms of how much long-term damage is suffered.

"Our view is that in all but the open prisons this should be a standard piece of equipment."

Although Mr Shaw admitted there was a risk of staff being held hostage by a prisoner armed with a knife, he said prisons would be ordered to carefully count the knives in and out every night to make sure none ever went missing.

Yesterday prison chiefs at Winchester welcomed the move, but said they had already introduced a system whereby one officer per wing carries the cut-down' knives as a precaution against attempted suicides.

Designated officer Spokesman Matthew Scott added: "We already have a designated officer on each wing and we have been using the knives for the past year.

"But as well as the knife, which is attached to the officer by a chain at all times, we also give the person carrying the knife a special radio so they are always contactable, and each knife is counted in at the end of each shift."

This year the number of prisoners across the UK taking their own life fell for the third year running to 67, down from 78 in 2005.