Members of Rapid Action Battalion on Thursday arrested a close associate of the chairman of Regent Hospital over issuance of fake coronavirus certificates from the hospital.   Sujoy Sarker, deputy director (media) of Rab Headquarters, said Tariqul Islam alias Tareque Shibli was arrested in a drive conducted in Nakhalpara area of the capital around 11am.   Important information was gleaned from him during primary quizzing, added Sujoy.