When the godman's supporters pelted stones at the police, they lobbed tear gas.
"We are trying to maintain law and order," said Police Commissioner R.P. Sharma. He said 12 people had been arrested for vandalism and hooliganism.
Police sources said several people were injured from both the sides in the clash. They included Deputy Commissioner of Police Satyabrat Bhoi.
Sharma said police would try to take police remand for the godman and his son to interrogate them.
A woman has lodged a complaint of sexual exploitation against the godman.
Police have slapped charges of wrongful restraint, wrongful confinement, obscenity and criminal intimidation against the godman.
Charges under the Arms Act have also been slapped against him following the recovery of two air guns and three 9 mm cartridges from the ashram.