Rab claimed to have arrested four members of a group involved in the illegal bitcoin trade from Dhaka's Darussalam area early today.

The arrestees are Hamim Prince Khan (32), the alleged ringleader; Rahul Sarker (21); Sanjeeb Dey alias Titas (28); and Sohel Khan (20), Rab said.

They are all from Faridpur district.

During primary interrogation, the arrestees admitted that they are involved in bitcoin and other virtual currencies trade through different virtual wallets, Commander Khandaker Al Moin, Rab's Legal and Media wing director, told a press briefing at Rab Media centre.

"They are also involved in credit card forgery. Sohel admitted to Rab that they earlier hacked and forged national and international credit cards and bought bitcoin through those," the Rab official said.

They also purchased pornographic content from the dark web using bitcoin and circulated those, he said.

The Rab official said Hamim, a tech expert, has been involved in bitcoin trade in the guise of software business.

He was a computer trainer but gradually turned to be a trainer for those interested in bitcoin business. Since 2017, he has trained at least 50 persons on bitcoin business since 2017, the Rab official said.

Besides, Hamim along with others had been running a Facebook page where they shared information on bitcoin and other cryptocurrency. The page has several thousand followers, he claimed.

Rab so far came to know about at least 14 virtual wallets belonging to Hamim. During primary interrogation, he told Rab that he transacted around Tk 1.5 crore this month through bitcoin and some other cryptocurrencies like Ethereum, Dogecoin and Nano. 

He also embezzled crores of money from his relatives and others in the name of investing in cryptocurrency -- luring them with huge profits.