Nine inmates committed suicide at Lincoln Prison over a 10 year period

The Howard League for Penal Reform said local jails have some of the highest national suicide rates, but it praised Lincoln Prison.

Between 1995 and 2004, nine inmates there killed themselves - about half the number in other similar prisons during the same period.

The study also said Morton Hall and North Sea Camp had no suicides.

Lincoln Prison governor Lynne Saunders said a number of measures had been introduced.

She said: "The big issue is awareness. Staff awareness and healthcare screening on reception needs to be very, very comprehensive.

"The warning signs in terms of people's potential for self harm need to be highlighted at the outset and we just need to communicate with each other, which we try our best to do."

John Webster from the Independent Monitoring Board at Lincoln Prison said: "Any death in custody is a very sad incident to all concerned, including the staff, but certainly at Lincoln there are many occasions when the staff have in fact prevented suicides and other forms of self harm which are not reported."

The prison suffered almost �3m worth of damage during riots in 2002 - said to be the worst since the Manchester Strangeways riot in 1990.