A youth accused general secretary of Hind Mazdoor Sabha Karmraj Singh (70) and two others of sodomy and threatening him, Circle Officer Anikl Yadav said.
According to the complaint, the accused had assured the complainant of providing him a job.
The complainant send a CD in this regard to SP Ram Bahadur Yadav and on his instruction an FIR was lodged late last evening, police said.
Karmraj has been arrested and efforts were being made to nab the two others, the CO said.