Less than an hour before a monitored remand prisoner was found dead in his Adelaide cell, his frantic mother rang the jail twice voicing concerns about him.

Pamela Payne said she told the prison staff: "I am telling you now, he is going to do something to himself", but was told there was an intercom in his cell and he had 24-hour access to nurses.

She also was told her son had been checked and was fine.

Ms Payne was giving evidence on Tuesday at the inquest into the death of Mark William Payne, 28, who died on June 2, 2011, after hanging himself in his cell in G Division at Yatala Labour Prison.

Amy Cacas, counsel assisting the coroner, said the cell had been constantly surveilled by CCTV and five minutes of every 30 minutes was fed back to monitors on a control desk.

"This means, at the time of his death, for 25 out of every 30 minutes, he would not be able to be monitored by control staff unless there was a physical check," she said.

Mr Payne was arrested on May 21, 2011 for trespassing, breach of bail and hindering police.

He was detained under the Mental Health Act following concerns about his mental well-being and his threats to kill himself.

After the seven-day order was revoked, he was admitted to Yatala and on the day of his death, he appeared in Elizabeth magistrates court, where he was refused bail.

Ms Payne said her son's mental health deteriorated after the break-up of a relationship and when he became involved with police for the first time.

"It was such trivial and stupid things he was being arrested for, he was ashamed of himself," she said.

Ms Payne was unable to see her son before the court appearance, but when he came into court, he smiled and mouthed: "It's okay, I'm alright."

But the last time she saw him alive was when he refused to look at her as he was taken from court after being refused bail.

"I told the lawyer `I know he is going to do something. I need to talk to him because he wouldn't look at me'," she said.

"I knew what state of mind he was in."

When she rang the jail, she was told she was not allowed to speak to her son as prisoners could only make calls during allocated times.

The inquest is continuing.

* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.