Detectives have questioned five people including three military policemen from the Comilla cantonment, where college girl Sohagi Jahan Tonu lived and was found dead.
The three men were at the Crime Investigation Department’s (CID) office from 4pm until midnight on Thursday, said Special Superintendent of Police Md Nazmul Alam.
He did not say who were the other two interrogated on Friday morning, but indicated one was a female friend of Tonu and the other a friend of her brother.
On Mar 20, the Victoria College student was found dead within several yards of her home inside the Comilla Cantonment, where her father, Yaar Mohammad, works as an office assistant.
Police suspected that she might have been raped before being murdered but her first autopsy report, though inconclusive about the cause of death, found no evidence of rape.
But a second autopsy was done after the body was exhumed on Mar 30 following a court order. It findings are not yet out.
Protests are still being held across the country with most blaming the authorities for failing to arrest anyone so far.
The CID has been investigating the sensitive case after it was passed on to it by the Detective Branch, which had got it from police.