Sarwar Alam, Executive Magistrate at RAB headquarters confirmed the matter on Tuesday.
Earlier on Monday, RAB conducted raids at the Uttara and Mirpur branches of the Regent Hospital and detained eight people.
Regent Hospital was one of the few private hospitals permitted to provide coronavirus treatment in March, when the coronavirus pandemic unfolded in Bangladesh.
The hospital has an agreement with the Directorate General of Health Services that it would treat coronavirus patients for free.
However, the hospital was charging patients as well as submitted vouchers to the government claiming patients were being treated for free, said the RAB Executive Magistrate.