The Human Rights Watch has called on the Bangladesh government to take urgent steps to confirm the whereabouts and release of men held by its security authorities outside the authority of the courts.
In a letter to Prime Minister Sheikh Hasina, that was made public on Saturday, the human rights body raised the issue.
Enforced disappearances have emerged as a key and pressing concern in Bangladesh, particularly since the period leading up to the January 2014 national elections, according to a UNB report.
Over 80 cases of secret detentions and enforced disappearances were reported in 2017, with seven of them killed later in so-called "gunfights," or "crossfire": euphemisms for extrajudicial killings. At least 17 are still missing, said a statement of the New York -based rights organisation published in its website.
"Secret detentions and disappearances have become a terrifying prospect for Bangladeshis, who fear that any criticism or political affiliation can lead to a knock on the door from the 'administration,'" said Brad Adams, Asia director at Human Rights Watch.
"As she nears the end of her third term in office, Prime Minister Sheikh Hasina should intervene personally to help families who are desperately looking for answers, and establish an independent authority to investigate and resolve this widespread problem."
Some of these disappearances appear to be politically motivated, with several members of opposition parties or their relatives still missing.
The government has promised repeatedly to investigate all allegations of human rights violations thoroughly and impartially. The issue was raised at the last United Nations Universal Periodic Review of the country's human rights situation, in April 2013. But reports of new cases continue.
During Human Rights Watch investigations into disappearances, witnesses confirmed the involvement of law enforcement agencies. In some cases, security personnel who carried out the detentions said that they were from the administration.
In other cases, family members and witnesses identified those responsible as members of the detective branch or the elite Rapid Action Battalion (RAB) of the police, or from the Directorate General of Forces Intelligence (DGFI) of the military.
Bangladesh should ratify the International Convention for the Protection of All Persons from Enforced Disappearances, Human Rights Watch said.
"In addition to the establishment of an independent authority, the Bangladesh government should invite relevant UN special mandate holders to conduct their own investigations," Adams said.
"These teams should all be given free and unfettered access to all detention sites and access to all victims and their families."