Lock down: Mental health concerns for suicidal prisoners
Questions have been raised about the length of time prisoners are spending in their cells in Northern Ireland's jails.
Twelve prisoners have taken their own lives over the last four years - two of them in the last fortnight.
A former inmate at Maghaberry Prison has told the BBC that despite having serious mental health problems, he was only allowed out of his cell for one hour a day.
One prisoner in Maghaberry took his own life this week. Another at Hydebank Wood attempted suicide there and died some days later in hospital.
As he died outside the prison it is not recorded as a prison suicide - but the circumstances of his death will still be investigated by the prisons ombudsman.
The former inmate told the BBC: "I was only allowed out of my cell for an hour, or an hour and a half a day. My state of mind when I went in was bad.
"I have mental health problems but I spent the time in prison crying on the phone to my family telling them if I didn't get released they'd be getting me home in a body bag."
The 23-year-old was in Maghaberry for a month for disorderly behaviour.
He attempted suicide there and was in a suicide watch cell for two days.
He said: "There's nothing in it. To me it would be safer if you're suicidal to be with someone rather than being on your own. At least they can ring the bell to get you help.
"All I did was sleep all day - I actually lay in bed that much I was getting back sores and everything."
Dr Linda Moore from the University of Ulster has carried out extensive research into prisons in Northern Ireland for the last ten years.
She said she was worried that lengthy lock-ups are becoming routine.
"You know yourself that being locked up 23 hours a day in an extremely barren environment would be extremely damaging to your mental health, even if you were well to start with.
"But for prisoners who already have serious mental health problems those very lengthy lock-ups with virtually no contact are both very unhealthy and the Special Rapporteur on torture in the United Nations has actually said it's inhuman and degrading treatment."
Northern Ireland Prisoner Ombudsman Pauline McCabe is about to leave her post after five years.
She said significant progress has been made to improve the regime in local prisons but added that no prisoner should be subjected to 23-hour lock-down.
"In order to keep prisoners safe there is probably nothing more important than making sure they have purposeful regimes, they have lots of human contact and where they have difficulties and problems they have an opportunity to share them and talk about them," she said.