Calcutta, April 14: A Trinamul worker in Salt Lake lodged a police complaint against Facebook posts lampooning his leader Mamata Banerjee the day his colleagues beat up a Jadavpur University professor for circulating an Internet joke on her.

The newly set up Bidhannagar police commissionerate, which is yet to have a cyber-crime wing, has forwarded the complaint to the CID for investigation.

Mahishbathan resident Suman Naskar alleged in his complaint at the Electronic Complex police station in Sector V that some youths were using Facebook and Twitter to spread “morphed pictures” of Mamata Banerjee and post “obscene comments” to malign her.

Naskar, in his mid 30s, told The Telegraph that he had lodged the complaint on Thursday because he did not want to see his party leader being humiliated. “I love my party and the chief minister and want to put an end to the posts that are making us more and more angry every day,” he said.

But unlike his party, he did not smell a political conspiracy in the posts and neither is he against cartoons. “I have no problems with cartoons. We see walls being flooded with them before the elections. I do not like the morphed pictures and the comments on Mamata Banerjee. She is the face of the state,” said Naskar.

He also feared that young supporters might lose faith in the party if social networks continued to host such posts.

K. Jayraman, the deputy inspector-general (operations) of the CID, said: “A case has been registered under the Information Technology Act. As Facebook is the most popular social networking site, we will write to its authorities in the US. We are yet to decide whether we will ask them to block some of the users. The cyber crime wing is working on the complaint.”

Another Trinamul leader said the cartoons, comments and morphed pictures on the social networks were the brainchild of “rivals”. “We must stop them at any cost,” he said.

For the Trinamul Congress, the Internet had been more of an opportunity than a threat before the Assembly polls. The party had launched a website to woo young voters and an email id, youth_students@aitmc.org, to open up a channel of communication with youngsters.

“We were flooded with emails from young people. Now we can see a change in their mindset who were once attracted to our organisation. If we can’t stop that, we may suffer an erosion in the youth vote bank,” a Trinamul leader said.

Youths have been vociferous in expressing their outrage after the arrest of professor Ambikesh Mahapatra, he added.