The “listeners” met and spoke to prisoners suffering from depression and mental health problems, including some who were suicidal.

Details of the number of calls have been released to mark the tenth anniversary of the scheme which operates in Maghaberry and Magilligan prisons, housing more than 1,300 prisoners.

The scheme has been operating in UK and Irish prisons for 25 years and is run by the Samaritans, who offer a three-month training course for prisoners who pass an initial selection and vetting process.

A programme for women prisoners and young offenders is being developed at Hydebank Wood College and Women’s Prison.

Volunteers working for the charity outside the prison answered a further 1,500 telephone calls from prisoners in Northern Ireland last year.

The Samaritans said research shows that prisoners are eight to 10 times more likely to die by suicide than the rest of the population.

According to the charity, around 23 per cent of male prisoners and 46 per cent of women prisoners suffer from anxiety and depression.

Gillian McNaull, the Samaritans’ regional prisons support officer who oversees the Listener scheme, explained: “The prisoners who are suffering emotional distress know that the Listeners know what life in prison is like and know what they are going through.

“I think there is something very redemptive about the process in that people who are in prison for punishment are being given a chance and are being trusted.”

“That can be really restorative for an individual to see that the people around them don’t stigmatise them but trust them to provide this service.”