Anwar Al Rokun was a healthy 40-year-old Yemeni journalist before his luck ran out and he was captured while returning to his home in Taez province from an assignment in Houthi rebel-held Sanaa.

Tortured for more than a year, he was emaciated and near unrecognisable when he was finally found by his brother in a prison in Al Saleh city in southern Yemen.

He died just days after his release, said Mohammed Marish, a media activist in Aden.

In late May, Anwar's brother had been at the prison to try and negotiate freedom for a friend when he stumbled upon his own sibling instead.

"He could not believe his eyes because Anwar looked completely different … he had turned into a skeleton," Mr Marish, a very close friend of the family, told The National.

"The Houthis allowed Anwar to go home as his health was quickly deteriorating and they knew he was going to die in their prison at any moment."

It took two days.

Anwar died from what doctors said were fatal wounds and serious health complications, attributed to mistreatment and being malnourished.

He had been without proper food for so long that his body was not responding to medication, Mr Marish cited a doctor as saying, noting that Anwar had told his family he was abducted and tortured for publishing reports on the Houthis’ violations against civilians.

The National could not reach Anwar's family, as their area in Taez remains under Houthi control.

The Abductees’ Mothers Association, a group run by about 20 women in Yemen, has been pleading for the release of their fathers, brothers and sons.

They urged UN envoy to Yemen Martin Griffiths to deal with the matter, saying: "The Houthi movement is trying to transfer detainees from the central prison to unknown destination(s) … our fears are increasing as the abductees may be subjected to atrocious violations or used as human shields."

AMA calls for urgently saving abductees from al-Hodeida prisons Abductees’ Mothers Association in al-Hodeida appeals to the United Nations’ envoy to Yemen, and local and international human rights organisations to intervene to save the lives of our abducted sons in al-Hodeida. pic.twitter.com/TQZT5HYbSp — رابطةأمهات المختطفين (@abducteesmother) June 30, 2018

Yemen's Minister of Human Rights Mohammed Askar condemned the Houthis’ torture of Anwar, and said it "reveals the hidden criminal face of the terrorist group".

Dr Askar urged international human rights organisations to document Anwar's case, adding that the ministry has recorded more than 16,800 cases of civilian abduction by the Houthis since 2015.

Maged Fadhayel, the deputy minister, said 6,000 of those abducted were still in Houthi prisons.

At least 1,200 civilians had been tortured, of which 133 people died as a result, Mr Fadhayel told The National.

Read more: Former prisoners traumatised by Houthi treatment

Many of the prisoners eventually released went home with permanent disabilities.

Jamal Al Maamari, 50, emerged in April after three years in a Houthi prison.

"The Houthis took me in March 2015 from my hotel room in Sanaa, where I was with my wife, to a detention centre west of the city," he told The National.

"I later learned that they abducted me because of a comment I had posted on Facebook."

Mr Al Maamari is paralysed from the waist down after enduring repeated beatings.

"As soon as I entered the prison, they started hitting me on the head with their guns until I passed out," he said. "When I woke up the next day I couldn't stand up because my spine was broken.

"My clothes were torn and covered with my own blood."

Mr Al Maamari explained the kind of torture he endured at the hands of the Houthis, who, he said, electrocuted him, burned him and used machinery to drill in his body.

"One of the times, a prison guard was burning my left leg [with a torch] until the skin started to melt off it so I asked him sarcastically whether he was hungry," said Mr Al Maamari.

"He retaliated by getting a drill and using it on my thigh."

Read more: Houthis hold Taez residents for ransom in makeshift prison

Another way to torture the prisoners was to deprive them of sleep, he said.

"I went for eight days and nights straight with no sleep, at times asking me to write my CV more than 40 times so as to stay awake," Mr Al Maamari told The National.

"They put me in a very small room with no electricity and no fresh air for more than eight months. I was not permitted to see daylight."

Abdulhadi Al Shami, 35, from the Ibb province, said he was repeatedly burned and had his nails pulled out.

"There was also psychological torture, where they would put us in a small room with snakes. There would be other rooms close to us, and we would hear fellow prisoners screaming because of the torture," he said.

"I saw many people die in the prison, and when they did die, they would bring a corpse and place it next to me."

Forty-six prisoners were released in Aden but the prosecutor did not provide details.