Nigerian authorities on Sunday said they had released nearly 500 Boko Haram suspects because of lack of evidence but a Bring Back our Girls spokesman said they had received no information on the question.
"We're not satisfied with the trials," Sesugh Akume told RFI. "There's supposed to be a Chibok desk in the government but they've told us nothing."
Mass trials of Boko Haram suspects began in October last year in special courts set up by the Justice Ministry.
The government was forced to act after Boko Haram insurgency was thrust onto the international spotlight in the aftermath of the Chibok schoolgirl kidnappings in 2014.
But nearly four years on, more than 100 of those girls are still unaccounted for.
On top of that, says Akume, the secrecy surrounding these trials means very little has been revealed that might indicate where the remaining girls are being held.
Low conviction rate
The limitations of the process are becoming clear.
To date 943 suspects have been released for lack of evidence - many of them had been in pre-trial detention for years.
Some convictions have been secured, however.
The government recently announced a second 15-year sentence for Boko Haram member Hurana Yahya for involvement in the kidnapping of the 276 Chibok girls in 2014.
He will serve a total of 30 years.
In all 45 people have been convicted and given custodial sentences and 82 have pleaded guilty, with some being freed after spending years in detention.
But, given the number of detainees, the overall conviction rate remains low.
Uyo Yenwong-Fai, a Boko Haram specialist at the Instutute of Security Studies in Pretoria, says it is not surprising that so many people have been released.
"There's not a lot to indicate that the preparation work before these arrests was thorough," she told RFI.
"I would imagine the government's hastiness is linked to the fact that they have been under a lot of pressure to get people tried."
Human rights groups continue to critise the use of mass trials. Amnesty says they tend to be hasty and focus on expediency not detail.
"One of the fundamental shortcomings of mass trials is that they are always rushed through," says Isa Sanusi of Amnesty Nigeria.
The number of minors among the detainees further undermines confidence in the process.
Among those released this weekend were a young girl and her three-month-old baby. She was forced to marry a Boko Haram fighter and was arrested trying to escape.
She had been detained for nearly 48 months.
Boko Haram leader still at large
Some progress has been made. The government has regained control of a sigificant amount of territory from by Boko Haram.
But, despite the offensive, the leader of the group, Abubakar Shekau, remains at large.
Three suicide attacks in Borno state killed 19 people on Friday, demonstrating that the group is still able to inflict carnage on the civilian population.
Even though the Nigerian government likes to give the impression that the war has been won, a lot of work remains to be done, says Yenwong-Fai.
"We're only seeing a little bit of the progress that has been made. We still need to address the leadership of Boko Haram," she points out.
Clearly that progress cannot come too soon for populations terrorised by Boko Haram.
In a video released earlier this month Abubakar Shekau said that he was "tiring of the calamity", which might indicate a change in his previously hardline position.