Three international rights bodies have urged Bangladesh to take immediate steps to locate journalist Shafiqul Islam Kajol, who has been missing since Tuesday.
They also called on the authorities concerned to drop the case filed by a ruling party lawmaker accusing 32 people, including Kajol and a newspaper editor, under the Digital Security Act.
The Human Rights Watch (HRW), Amnesty International, and Committee to Protect Journalist (CPJ) separately made the calls on Friday.
"The case of Shafiqul Islam Kajol is deeply concerning, particularly given Bangladesh authorities' record of abducting people and holding them in secret detention where their safety and lives are at risk," said Brad Adams, Asia director of Human Rights Watch.
"The Bangladesh government should take immediate steps to locate Kajol and bring him to safety," he added.
Saifuzzaman Shikhor, a ruling-party lawmaker from Magura-1, on Monday filed the case against Kajol, Editor-in-chief at the daily Manabzamin Matiur Rahman Chowdhury, and 30 others on charge of publishing a report with "false information" and circulating it on social media.
Kajol, editor of a biweekly newspaper, went missing a day after the case was filed.
His son Monorom Palak said his father left home for office around 3:00pm on Tuesday and as he did not return by 10:00pm, the family members called him only to find that two of his mobile phones were switched off.
Kajol's family suspects that he was abducted and has urged authorities concerned to help ensure his safe return.
The family on Wednesday filed a general diary with Chawkbazar Police Station in this connection.
"Bangladeshis should not live in fear of abduction if they share something on Facebook," Adams said in the statement, adding "The government needs to seriously investigate the many cases in which family members allege that the victim was picked up by security forces but whose whereabouts remain unknown."
The HRW said the international community and Bangladesh civil society have repeatedly called on the government to repeal the vague and overly broad segments of the Digital Security Act, which "facilitates abuse".
In the statement, the HRW said Bangladesh authorities had a history of arbitrary detentions and forced disappearances. While some people are later released or formally taken into custody, officials have in some cases said they were killed in alleged gunfights with the security forces or in crossfires.
Many of these victims were targeted as members of the political opposition. In recent years, however, there have been cases in which security forces have disappeared individuals in what appear to be the result of personal retribution by members of the ruling elite, it added.
Meanwhile, the CPJ, a New York-based NGO that promotes free press and defends the rights of journalists, issued an alert saying Bangladesh authorities should spare no effort to locate Kajol.
"The disappearance of journalist Shafiqul Islam Kajol is especially concerning after he was named in a dubious defamation complaint filed by a member of parliament under the draconian Digital Security Act," said Steven Butler, CPJ's Asia program coordinator.
The Amnesty International issued an "urgent" appeal for the Bangladesh government to launch an independent investigation to determine the fate and whereabouts of Kajol and keep his family fully informed at all times, and ensure he is immediately released if under state custody.