The main accused in the murder case of special public prosecutor Rathish Chandra Bhowmik died at Rangpur Medical College Hospital in police custody on Saturday.
The deceased was identified as Kamrul Islam.
Ratna Roy, senior jail superintendent of Rangpur Central Jail, said Kamrul had been suffering from depression.
He got injured critically while trying to commit suicide by hanging herself with his bedsheet at around 5:00 am.
Islam was later taken to the hospital where doctors declared him dead.
According to UNB reports, Rathish, a public prosecutor at the Special Judge's Court in Rangpur, was killed over alleged extramarital affairs between his wife Snigdha Sarkar Dipa and Kamrul on March 29.