Members of Rapid Action Battalion (Rab) on Tuesday arrested another accused, who is a relative of  prime accused Ajmeri Osman in a case over the killing Tanvir Mohammad Twaki, from a bus on Dhaka-Chattogram highway in Siddhirganj area of Narayanganj district.

The arrestee is Andullah Al Mamun alias Jamai Mamun, 40, son of Abdur Rahim of Barishal district. He is a close relative of Ajmeri Osman, son of AKM Nasim Osman, former lawmaker of Narayanganj-5 constituency.

Twaki murder: RAB visits Ajmeri Osman's 'torture cell' in Narayanganj

Tipped off, a team of Rab-11 intercepted a Khagrachari-bound bus on Chittagong Road and arrested Mamun early this morning, said a press release of Rab issued on Tuesday afternoon.

Seventeen year old Twaki went missing from in front of his house in Narayanganj on March 6, 2013.

Rafiur Rabbi, father of Twaki, filed a general diary in this connection.

Twaki was later found dead on the banks of the Shitalakhya in Narayanganj on March 8. Then a case was filed with Sadar Model Police Station.

Later, RAB's investigation revealed the involvement of Ajmeri Osman, son of Narayanganj late MP Nasim Osman and nephew of former MP Shamim Osman and his associates in the murder of Twaki.

Eleven people were directly involved in killing Twaki at a ‘torcher cell’ named ‘Weiner Fashion. Mamun was among them.

After the fall of the AL-led government, RAB has so far arrested five people-Yar Mahmud Parvez, Safayet Hussain Shipon, Mamun Mia, Kajal Howladar and Jamshed Sheikh- for their suspected involvement in the murder case.

RAB said that all those arrested are close aides of the sons of late Narayanganj MP Nasim Osman and former MP Shamim Osman.

Among them, Jamshed Sheikh is Ajmeri Osman's personal driver.

Later, Mamun was produced before the court and the court sent him to jail.

The court also fixed October 6 for hearing the remand petition, said Court inspector Abdur Rashid.