PBI officials probing the Mitu murder case will send the two books, seized from her husband and ex-police official Babul Akter as "evidence of his extramarital affairs", to the CID for forensic examination.

Babul got the two books -- "Taliban" written by Ahmed Rashid and "Best Kept Secret" by Jeffery Archer -- as gifts from a woman in 2013, and he reportedly wrote about his extramarital affairs on different pages of the books, said sources in the Police Bureau of Investigation.

The books were seized from Babul, now in jail, after his father-in-law Md Mosharraf Hossain on May 12 filed the case with Panchlaish Police Station against him and eight others over Mahmuda Khanam Mitu's murder in 2016, they said.

In the case statement, Mitu's father mentioned that her daughter found the books on Babul's bookshelf and a brawl had taken place between the two when she asked about the writings in those.

Inspector Santosh Kumar Chakma, investigation officer of the case, said "We found in the books Babul's writings about several events in 2013.

"We will send those to handwriting experts at CID's forensic lab to confirm whether it's Babul who wrote those…," he told this newspaper yesterday.

The IO also mentioned that the books also contain writings of a woman with whom Babul, ex-superintendent of police, reportedly had an extramarital affair.

Meanwhile, a Chattogram court yesterday ordered the Chattogram jail authorities to take necessary steps to ensure Babul's treatment inside the prison as per the jail code.

Metropolitan Magistrate Mehnaz Rahman passed the order following a plea from Babul.

Arifur Rahaman, counsel for Babul, said, "Babul is ill. We appealed to the court to send him to hospital for treatment. After the hearing, the court directed the senior jail super to take steps to provide him with treatment as per the jail code."

On June 5, 2016, Mitu was stabbed and shot dead while she was taking her son to his school-bus stop at the port city's GEC intersection. After the murder, Babul filed a case against three unidentified men with Panchlaish Police Station.

On May 11 this year, the Chattogram PBI summoned Babul to its office for questioning over the murder.  He failed to give satisfactory answers to the detectives and was taken into PBI custody.

The following day, Mitu's father filed a murder case against eight people, making Babul the prime accused in the case.