Md Gias Uddin, senior jail superintendent of Kashimpur High Security Prison, initiated the case at Gazipur Sadar Police Station on Friday.
Police Sub-Inspector Syed Bayezid, who made the inquest report in the presence of Gazipur Executive Magistrate and Assistant Md Wasim Uz Zaman Chowdhury in the morning, said Mushtaq had scars of possibly past infection on his back.
The writer also had small reddish dark marks on his right hand. The authorities suspect these were caused while he was being taken to the hospital or getting him on or off the car.
The doctors collected viscera samples for chemical analysis at the laboratory of police’s Criminal Investigation Department and histopathology tests at Dhaka Medical College Hospital.
The body was handed to the family after the inquest and post-mortem examination. The hearse carrying the body reached his home in Dhaka’s Lalmatia in the afternoon.
The writer’s cousin Dr Nafisur Rahman said they were planning to bury Mushtaq at Azimpur Graveyard after funeral prayers at the local mosque.
The protesters rallied and marched in procession blocking the streets for around an hour.
Besides fair investigation into Mushtaq’s death, they demand cancellation of the Digital Security Act.
Home Minister Asaduzzaman Khan Kamal at an event in Chattogram said he hoped the autopsy report would reveal the cause of the death of Mushtaq, who had no reported ailment.
A committee will be constituted ‘if necessary’ to investigate the writer’s death, he added.
Hailing from Narayanganj’s Araihajar, Mushtaq was one of the entrepreneurs of crocodile farming in Bangladesh. He actively wrote about different issues on social media.
The Rapid Action Battalion arrested him at his home in Dhaka’s Lalmatia and cartoonist Ahmed Kabir Kishore at Kakrail on May 5 last year amid the coronavirus crisis.
The duo, along with nine others, were charged with propagating disinformation against the government on social media.
The judge rejected several bail petitions of Mushtaq and Kishore while activists demonstrated on several occasions demanding their release.
The charges brought by the RAB in the case include running a disinformation campaign against Bangabandhu, the Liberation War and the pandemic to hurt the image of the government or state and create instability.
The RAB also claimed to have evidence that Mushtaq and Kishore had “conspired” with Bangladeshis abroad on WhatsApp and Messenger apps.