A notification issued by the home department suspended Kumar, who was the former Saran range DIG with immediate effect, Principal Secretary (Home) Amir Subhani said.
He, however, refused to divulge further details about the ongoing probe in the extortion case.
Liquor trader Tunaji Pandey, who has his business in several districts of the state, had alleged that Kumar had demanded Rs 10 crore from him through his aides and threatened to implicate him in false cases if he failed to meet the demand.
The charge against the former Saran range DIG and others were established during a preliminary probe by putting surveillance on mobile phones of the accused persons, including Kumar.
Police later arrested three aides of Kumar and recovered Rs 5 lakh cash and documents from their residences in Patna and other locations.
Taking serious view of the matter, the state government had transferred Kumar to the police headquarters here and handed over the probe to the department's Economic Offence Wing.
