Chadian officials have said that 44 Boko Haram militants who were captured together with 14 others have died of poisoning while in detention in the country.
The country’s public prosecutor said investigations have started into the circumstances under which the suspects died in jail.
The investigations were launched after four autopsies showed a lethal substance caused their deaths.
Youssouf Tom, the state prosecutor said on state television that “Forty of them were buried and the other four were taken to a pathologist, whose report revealed that a lethal substance was consumed, leading to heart problems in some and severe asphyxiation amongst others.”
According to Chad’s justice minister, Djimet Arabi the prisoners were not ill as he rejects claims that they were placed in poor conditions.
The 58 Boko Haram militants were captured in recent major army operation against the group around Lake Chad.
The militants were found dead on Thursday morning, according to the public prosecutor.
Chad has already claimed victory over the militant group’s activities within its territory after recent major operations.
President of Chad, Idriss Deby visited Chadian troops in areas Boko Haram and other militants have been launching attacks against Chadian soldiers.
Chad destroyed five bases of the Boko Haram in response to an attack on a military base on March 23 that killed 98 Chadian soldiers.
Since Boko Haram launched its bloody insurgency in 2009 in northeastern Nigeria more than 30,000 people have been killed and nearly 3 million displaced.
Boko Haram’s activities have extended beyond Nigeria to other countries within the Lake Chad Basin covering Niger, Chad and Cameroon.