When the BNP lost power in 2006 to 2007, an army-backed caretaker government pursued an aggressive anti-corruption drive, and Rahman became a prime target. He was arrested on March 7, 2007, and faced an expanding array of cases including corruption, money laundering, extortion, and more. In some instances, he was accused of being involved in plots tied to high-profile violence, including cases related to attacks on political rallies. One major case alleged that during the BNP government, Rahman and his associate Giasuddin Al Mamun laundered approximately Tk 20.41 crore to Singapore. Initially acquitted in 2013, that verdict was overturned in 2016 by the Bangladesh High Court, which sentenced Rahman to seven years’ imprisonment and fined him Tk 20 crore. The convictions were stayed by the Supreme Court in December 2024, pending appeal.