Members of Counter Terrorism Division of Chattogram Metropolitan Police (CMP) claimed to have arrested the "IT expert" of banned militant outfit Ansar Al Islam from port city's Khulshi area on Friday night.
The arrestee is Shakhawat Ali alias Lalu (40), a resident of Wasa area under Khulshi.
According to investigators, the alleged militant operative trained in Syria from Hayat Tahrir Al-Shams (HTS) in 2017.
Hasan Md Shawkat Ali, deputy commissioner (DC) of CT division, said Shakhawat was arrested in front of Central Ahle Hadith Jame Mosque of South Khulshi.
They also seized some books and documents related to Ansar Al Islam from him, he said.
Shakhawat went to Turkey from Chottogram in April 2017 and then entered Syria illegally. There, he received training under HTS, added the DC.
"He came to Bangladesh on March 22 this year from Indonesia. He used to upload audio, video and other contents related to militancy and maintained the outfit's online activities," the DC said.
Investigators said Shakhawat joined Ansar Al Islam with the help of his brothers-in-law Mamun and Arif in 2012.
DC Hasan said he had also met with absconding top militant Major Zia earlier in 2013.
A case has been filed against Shakhawat with Khulshi Police Station yesterday.
During primary interrogation, Shakhawat claimed that he has degrees from India and the UK and he completed multiple IT-related diploma courses in the country.
He said he completed his MSc degree at a university in the UK in 2009-2010 and returned to Bangladesh in 2011.
In Chattogram, he met one Omar Faruk, an AC salesman in Wasa area, at a mosque near his home. They became good friends.
In December 2011, Faruk introduced him to one of his friends Amzad Hossain Arif, who also gave him IT training.
Ahmed Payer, additional deputy commissioner of CT, said, "We are verifying the information. We have seized his documents, laptops, phones and passport."