Families of 37 artisinal miners who died in custody in Nigeria want swift justice and the return of property seized during their arrest, saying no financial compensation will make up for their loss.

A presidential panel on Tuesday found that the detainees, who were suspected of being illegal miners, had died from overcrowding, extreme heat, dehydration and neglect while being held by the Nigeria Security and Civil Defence Corps (NSCDC) in Niger state last month. 

Nigeria's government welcomed the panel's findings, and Interior Minister Olubunmi Tunji-Ojo said the panel's report had been sent to the attorney-general for immediate judicial action. He did not respond to requests for comment on when victims' families and survivors would receive compensation.

The deaths, including of teenagers, triggered protests in Nigeria, raising new concerns about conditions in detention facilities and the treatment of suspects awaiting trial.

"What we wanted was for our children to be alive and return to us," said Zainab Salihu, whose son was among the dead.

She said the deaths in detention had led to the deterioration of the health of her husband, who later died. Reuters was unable to verify the circumstances of her husband's death.

"No matter how much money they give us, it will never bring our children back," Salihu said.

Dantala Tanko, whose 25-year-old son Suleiman died in detention, is struggling to come to terms with his loss.

"Now he is gone, and this is deeply painful for me. I know he will never return," he said after praying at his son's grave.

Some survivors said they appreciated the investigation's findings, but wanted accountability.

"Officers who demonstrate such disregard for human life should not remain in positions of authority. They must be held accountable, and appropriate disciplinary action should be taken," said said 25-year-old Dauda Shehu.

Abdulsalam Yakubu, 23, said government action had been slow. He said he wanted the government to return motocycles, phones, mining equipment and gold which he said had been seized during the victims' arrest.

"We have suffered enough. We are asking for justice, the promised support, and the return of our property so that we can begin to rebuild our lives," he told Reuters.