Sagira Morshed Salam was killed 30 years ago over a domestic dispute -- as opposed to the previous narrative that it was a mugging incident gone wrong, Police Bureau of Investigation (PBI) yesterday claimed to have found in its probe.

Her brother-in-law had "hired one of his patients with Tk 25,000 to teach her a lesson", they said.

The information came to light after PBI on Wednesday arrested Maruf Reza (49), who was allegedly hired by the couple -- Dr Hasan Ali Chowdhury (70) and Sayedatul Mahmuda Shaheen (64).

On July 25, 1989, 34-year-old Sagira was shot dead on the road, while going to Viqarunnisa Noon School to pick up her daughter Saharat.

Sagira's husband Abdus Salam Chowdhury filed a case accusing unnamed people with Ramna Police Station the same day. But trial of the case remained halted for the last 28 years, following a High Court order.

Speaking at a press conference in the capital, PBI chief Banaj Kumar Majumdar said Dr Hasan, Abdus Salam and Samsul Alam Chowdhury are brothers who lived with their families at a house in Rajarbagh.

Disputes grew among Sagira and her sister-in-law Shaheen regarding different household matters, and in early 1989, Shaheen told her husband to teach Sagira a lesson, Majumdar added.

Maruf, now a real estate businessman, was a notorious criminal of Siddheshwari area at that time, and used to be Dr Hasan's patient.

The PBI official said Dr Hasan hired Maruf with Tk 25,000 to "teach Sagira a lesson", however, he didn't give the money to Maruf after the incident.

On July 25, 1989, Dr Hasan called his brother-in-law Anas Mahmud Rezwan (59), now an NGO official, and told him to stand in front of Mouchak Market to escort Maruf to identify Sagira.

Around 4:40pm, Anas and Maruf followed Sagira on a bike. Before it could reach Viqarunnisa School, the duo halted the rickshaw of Sagira. Maruf tried to snatch the bag and a bracelet from Sagira. At the time, as Sagira identified Anas, Maruf opened fire on her and fled the scene, the PBI official added.

PBI have arrested the four over the last week, who have given confessional statements to court, admitting their involvement in the murder of Sagira.

Sagira's husband Abdus Salam was also present at yesterday's press conference. He expressed faith in PBI's investigation to get justice this time.

After being stayed for 28 years, the HC bench of Justice M Enayetur Rahim and Justice Md Mostafizur Rahman lifted the stay order on June 26, and cleared way for the lower court to resume the proceedings.

The HC bench also ordered PBI to complete further probe into the case in two months, and directed the trial court to finish its proceedings in three months.

The PBI yesterday said it would need two more months to complete the investigation.

Earlier, the detective branch of police submitted a charge sheet to the lower court concerned against one Minto alias Mantoo alias Moron. On January 17, 1991, a Dhaka court framed charges against him. The court also recorded statements of seven witnesses in the case.

Name of Maruf Reza, a relative of former home minister Mahmudul Hasan, came to light when the trial court was recording statements of the witnesses.

Then the lower court directed police to further investigate into the case on May 23, 1991.

Later, Maruf Reza filed a revision petition with the HC, challenging the lower court order for further investigation. On July 2, 1991, the HC stayed the trial proceedings of the case and further probe.

Reza, who had been arrested, was later exempted from the case. Mantoo, who had also been arrested in connection with the case, was released from jail on bail.

However, PBI yesterday couldn't say whether Mantoo had any connection with the case.