He was allegedly beaten by the activists of the Gurdwara Bachao Sangarash Committee last night, they said.
The police said Singh, a former MLA, has lodged a complaint, claiming that he was changing his clothes in a room in the gurudwara when around a dozen people forcibly entered the shrine and started beating him.
On his complaint, the police registered a case under various sections of the Indian Penal Code against the accused.
Singh claimed he did not consider Gyani Gurbachan Singh as Jathedar Akal Takht as he was removed by the Sarbat Khalsa which appointed Gyani Dhian Singh Mand as Jathedar Akal Takht.
He claimed that he had appeared before Dhian Singh Mand who declared him 'tankhahia' or guilty of religious misconduct on October 12 and asked him to perform 'sewa' or service at Harmandar Sahib, to wash utensils at the community kitchen hall, clean shoes of the 'sangat' and listen to 'kirtan'.