"We have arrested ARCF operator Sheikh Obaidullah, who, according to our information, is wanted by the Indian authorities," Deputy Police Commissioner of Detective Branch Monirul Islam told PTI.
Islam said Obaidulah, a resident of West Bengal's Haora district, was trying to expand the network of ARCF, which had claimed responsibility for the terrorist attack on the American Centre in Kolkata in 2002 and closely linked to Harkatul Jihad Bangladesh and Pakistan-based Lashkar-e-Tayiba.
The official said Obaidullah, who also identified him as Abu Jafar, was detained from western Shariatpur district "several days ago" but it took them sometime to confirm his identity as he was trying to conceal it.
Security officials familiar with the terrorist outfits in the region said ARCF represents the growing nexus between organised crime and terrorism, since it was raised as a marginal group in December 2001 along the north-western Bangladesh-India frontiers.
Islam said they tracked down Obaidullah as an investigation was underway to unearth the network of Indian underworld don Dawood Ibrahim in Bangladesh since the arrest of their several operatives including Dawdood Merchant in May.
ARCF was named after its founder Asif Reza Khan, who was killed at Rajkot in Gujarat on December 7, 2001, when he tried to escape from police custody.