Police arrested another member of Rapid Action Battalion (RAB) from Farmgate area in the capital on Friday in connection with the sensational seven murders in Narayanganj.
The arrested RAB official is identified as Purnendu Bala, deputy director of RAB.
Acting on secret information, a team of police raided the area and arrested Bala around 1:25pm, RAB sources confirmed on Saturday morning.
He was later handed over to the Detective Branch of police, the sources added.
RAB Media Wing director Mufti Mahmud Khan told media that Purnendu Bala went on leave in last April, but he did not join office later.
"Even Bala did not appear before the investigating officer despite he was summoned in the case. Since then he was absconding. So, RAB detained him as a suspect," he added.
Police already arrested eight RAB men in two separate cases in connection with the sensational seven-murder.
Lt Col Tareque Sayeed Mohammad, Maj Arif Hossain and Lt Commander MM Rana, who had been arrested earlier, confessed their involvement in the gruesome murders.
Later, on August 26, police arrested five more RAB members.
Narayanganj city panel mayor Nazrul Islam, his driver and three associates, and senior lawyer Chandan Sarker and his driver were abducted separately on April 27.
Their bodies were found floating in the river Shitalakkhya a few days later.