Former military member Hafizur Rahman was released on bail from Cumilla Central Jail on Tuesday in the murder case of Sohagi Jahan Tanu.
Senior Jail Superintendent Md Shah Alam Khan said the release was completed at 7:05pm after the required procedures.
A High Court bench comprising Justice Zakir Ahmed and Justice Sathiqa Hossain granted Rahman bail on 2 August.
The accounts differ on whether investigators arrested Rahman in Keraniganj on 21 or 22 April.
After he was brought before a Cumilla court, investigators sought seven days of remand and a judicial magistrate authorised three days.
Investigators collected Rahman's DNA sample and submitted a DNA-related report to the court after testing.
The Police Bureau of Investigation said evidence from Tanu's clothing yielded complete DNA profiles from more than one male.
A court has permitted collection of blood samples from two further suspects for comparative DNA testing against that evidence.
The court also issued arrest warrants on 8 June for two other suspects and directed that Interpol red notices be pursued, investigators said.
Tanu, a history student at Cumilla Victoria Government College, went missing while travelling for tutoring in the Cumilla cantonment area on 20 March 2016, and her body was found the following day.
Her father filed a murder case against unidentified people.
The investigation was transferred to the Police Bureau of Investigation in October 2020, and Inspector Tarikul Islam said efforts to locate suspects and collect DNA samples are continuing.