Cameroon has acknowledged that more than two dozen Boko Haram suspects died in custody late last year, but a government spokesman denied the country's army was carrying out regular human rights abuses in its crackdown on the extremist group.
The 25 suspects were found dead in their cell a day after being arrested in December, communications minister Issa Tchiroma Bakary said.
They were part of a group of 56 detainees and the cause of their deaths is still being determined, he said.
"I can already state here that at this stage of investigation no evidence has been established to corroborate that these persons were deliberately killed," Mr Bakary said.
He added that a senior military official had been removed from his post and was being investigated over the deaths, though he did not identify the person by name.
In January, the Network of Human Rights Defenders in Central Africa, based in the capital Yaounde, cited "reliable sources" in claiming that 50 Boko Haram suspects had suffocated to death in their cells before being buried in a mass grave.
The group's report accused the army of engaging in rights violations including torture "with impunity".
Boko Haram has been fighting a near six-year insurgency against the Nigerian government, killing thousands and carrying out mass kidnappings, including of schoolgirls.
The conflict has taken on an increasingly international dimension in recent months.
Cameroon's northern region was repeatedly targeted by Boko Haram before the country signed up to participate in a multinational force that has dislodged the group from a score of north-eastern Nigerian towns in recent weeks.
Nigeria has acknowledged it is getting help from regional security operatives amid reports that South Africa and other foreign contractors are involved in the fight against Boko Haram.