Nigeria has appointed a panel to investigate the deaths of 37 detainees.
The men died while being held by the country’s civil defence force in Niger State.
They had been arrested on suspicion of illegal gold mining.
President Bola Tinubu has called for a full investigation into the deaths.
Meanwhile, the government has given a 10-member panel two weeks to examine what happened.
37 detainees die in custody
The men were found dead in a holding cell in Minna on Thursday.
Minna is the capital of Niger State.
The Nigeria Security and Civil Defence Corps (NSCDC) had arrested the men on suspicion of illegal gold mining.
According to the Associated Press, survivors said the cell was crowded and poorly ventilated.
One survivor also made a serious allegation.
He said a substance that irritated their throats and noses was sprayed into the cell.
Survivors also said their calls for help were ignored.
However, authorities have not yet established the cause of the deaths.
Panel given two weeks
Interior Minister Olubunmi Tunji-Ojo announced the new panel.
It has 10 members from different backgrounds.
They include a retired intelligence officer and a medical expert.
A human rights activist and a miners’ representative are also part of the panel.
The panel has two weeks to complete its work and submit a report.
It will examine possible negligence, misconduct and responsibility for the deaths.
20 officers and guards suspended
Tunji-Ojo said 20 NSCDC officers and guards had been suspended.
They were connected to the arrests and detention of the men.
The head of the unit was also suspended.
However, the suspensions do not establish responsibility for the deaths.
Tinubu has called for the investigation to be full and transparent.
The investigation is expected to establish what happened inside the holding cell and how the 37 men died.