Mumbai: An FIR has been registered against a man in the neighbouring Navi Mumbai for allegedly posting "offensive and humiliating" messages about NCP chief Sharad Pawar on a social networking site, police said on Friday.

No arrests have been made, with police saying appropriate action would be initiated after a proper probe. They also did not reveal the content of the messages posted on Facebook.

According to Nerul police station, an NCP worker saw the posts on Facebook about Pawar and found them "offensive and humiliating". He complained to the police on Wednesday, following which an FIR was registered against one Pravin Pisal.

"The FIR was registered under section 66 A (punishment for sending offensive message through a communication service) of the IT Act. We have not arrested Pisal as we want to first make a thorough investigation into the case," Rajkumar Chaphekar, senior inspector at the police station, told PTI. The officer, however, did not divulge the name of the complainant.

Investigators are taking help of legal experts before initiating any action against the accused, said another officer adding that Pisal would be questioned in this connection.