Quader, also former vice president of Jatiya Party, was picked up from his residence on Tuesday afternoon and taken to Gaibandha, said Rezinur Rahman, senior assistant superintendent of police (Gaibandha circle).
Inspector Mahbub Alam of the Special Branch of police in Gaibandha who was present during the detention said they booked him for interrogation over the the much-hyped murder.
When contacted, Inspector General of police AKM Shahidul Hoque told the Dhaka Tribune that Quader is one of the masterminds of Liton's murder.
“He [Quader] had Liton killed. It is clear to us,” said the IGP, adding: “He planned the murder to be rid of competition and become an MP yet again.”
Quader's elder brother Khizir Khan said the detention was a conspiracy against his sibling.
Gaibandha SP Md Ashraful Islam said police had arrested Quader's chauffer, domestic help and the caretaker of his house from the district's Bridge Road area on Tuesday morning.
A primary interrogation led the trio to confess to being linked with the murder. Based on their information, police detained Quader, he said.
Quader and his family reside in Rahmannagar area of Bogra town in a five-storey building which also has a clinic where he and his wife Dr AJU Nasima Begum, a gynaecologist, see patients.
Nasima told reporters that Mahbub, OC Amirul Islam of detective branch of police in Bogra and several other members of Sundarganj police entered their house around 5pm and took Quader away. They had also conducted an hour-long search of their home.
“When we demanded to see an arrest warrant, they could not produce one,” she claimed.
The search yielded nothing since Quader had deposited his licenced firearm at Sundarghanj police station a few days earlier.
According to Quader's wife, police, both in uniform and plain clothes, had besieged their house since 10pm on Thursday, ever since the former MP had returned from Dhaka.
Quader had been elected as MP in the 2008 parliamentary election as candidate for Awami League-led 20-party Grand Alliance. He recently informed reporters that he would not run for by-polls in the constituency, which was vacant after Liton was shot dead at his village home in Sundarganj’s Masterpara on December 31 last year.
Nasima alleged his change of heart in terms of contesting in by-the election was the reason for their being confined at home.
On Friday, Quader told reporters that Gaibandha SP Ashraful Islam had informed him over phone that they tightened security around his house for fear of a possible militant attack on him.
It should be noted, on February 7, the High Court bench of Justices Obaidul Hassan and Krishna Debnath ordered the government to withdraw Gaibandha SP Md Ashraful Islam from duty for his involvement in the arson cases at Santal villages on November 6 last year.
The court asked the home secretary to implement the order and update it within four weeks.
Since being detained, Quader was scheduled to be produced at a Gaibandha court for his confessional statement, but as of 10:30pm Tuesday, there has been no update on the matter.
Gaibandha police will hold a press conference regarding the murder investigation at 10am on Wednesday.