A professor of Kolkata's Jadavpur University was arrested on Friday for allegedly circulating defamatory e-mails directed at Chief Minister Mamata Banerjee, among others. His neighbour, Subrata Sengupta, was also arrested.

Ambikesh Mahapatra, physical chemistry professor, and Mr. Sengupta were later released on bail amid severe condemnation of the arrests by a cross-section of the city's intellectuals and politicians, who pointed out that the move smacked of authoritarianism on the part of a government bent on stifling the freedom of expression.

The two were arrested in connection with forwarding an e-mail containing a graphic with a humorous reference to Ms. Banerjee replacing Dinesh Trivedi with Mukul Roy as Railway Minister. The graphic uses photographs of the three Trinamool Congress leaders and a clever play of words with dialogues from Satyajit Ray's detective masterpiece on celluloid “Sonar Kella.”

It caricatures a discussion between Ms. Banerjee and Mr Roy on how to replace Mr. Trivedi as Railway Minister.

Mr. Mahapatra and Mr. Sengupta were arrested on the basis of a complaint from a local Trinamool Congress leader. They were booked on charges of defamation, outraging modesty of a woman and hacking.

Soon after his release, Mr. Mahaptra joined a rally organised by teachers of the university to condemn his arrest.

“Before I was arrested by the police, I was beaten up by a group of youths on Thursday evening who forced me write an apology insisting that I declare that I was an active worker of the Communist Party of India (Marxist). The e-mail was forwarded in good humour,” Mr. Mahapatra told journalists at the university.

He felt there was nothing objectionable in the content of the mail. His only regret was that he forwarded the e-mail using an id of the secretary of the housing complex he resides.

Meanwhile, there were angry protests on the campus. Hundreds of teachers, non-teaching staff and students took out rallies, shouting slogans against his arrest. Posters were pasted and graffiti scrawled on the university walls.

Condemning the arrest, Vice Chancellor of the university Pradip Narayan Ghosh said police cannot take such action just for circulating an e-mail. “There must be something else.”

Defending the arrest, certain Ministers described Mr. Mahapatra's action as “demeaning” the leaders depicted in the graphic.