Salman F Rahman, private industry affairs adviser to former prime minister Sheikh Hasina, and Anisul Huq, former law minister, were arrested at the capital's Sadarghat today.

They were arrested in a case filed with New Market Police Station, said Mainul Hasan, the commissioner of the Dhaka Metropolitan Police.

Acting on a tip off, police arrested them in the Sadarghat area while they were trying to flee through the waterway, he said.

The commissioner, however, did not mention where they were heading to.

Police sources said the duo was arrested as instigators of the killing of Dhaka College student Sabuj Ali, 26, on July 16.

Sabuj's elder brother Nurnabi filed the case on July 17 after identifying his body at Dhaka Medical College morgue.

According to the first information report, Nurnabi learned around 3:00pm on July 17 that his brother Sabuj was beaten up by BNP-Jamaat men and he was admitted to Dhaka Medical College Hospital.

Nurnabi then went to the hospital and found the body.

This is the first arrest of bigwigs of the Sheikh Hasina-led administration after its fall on August 5.

Over 550 people, including students and police, were killed in the violence during the student protests that turned into an anti-government movement.

Salman was a lawmaker from Dohar and vice-chairman of the Beximco Group. He is also the chairman of IFIC Bank and holds key positions in many business associations.

Political analysts say he was one of the influential figures among the policymakers in the Awami League government.

Anisul, a reputed lawyer, was the law minister for three consecutive times after 2014.

Before that, he was the chief counsel and special prosecutor for the Anti-Corruption Commission, and the chief prosecutor for the Pilkhana carnage case.

His father Serajul Huq was a prominent organiser of the Liberation War in 1971. Anisul was the Chief Special Prosecutor for both the Bangabandhu Murder Case and the Jail Killing case.

He was one of the few cabinet members of the immediate past government who tried to diffuse the student protests for quota reform.