The national anti-graft body sent a letter, signed by the chief of the inquiry team and ACC director Syed Iqbal Hossain, to Immigration Police of the Special Branch on Wednesday requesting it to take steps so that they cannot make any trip abroad.
On September 30, the ACC launched investigation against those who amassed wealth through casino business.
Syed Iqbal Hossain was given the charge of inquiry while its Director General (Special Investigation) Sayeed Mahbub Khan made investigation officer.
Earlier, Bangladesh Financial Intelligence Unit (BFIU) directed all scheduled banks to send account details of a number of people, including Nurunnabi and his wife Farzana Chowdhury Ratna.
Elite force Rapid Action Battalion (Rab) launched the anti-crime drive on September 18.