The Congress on Friday sought to disapprove of the arrest of a professor by West Bengal police for allegedly posting a cartoon showing Chief Minister Mamata Banerjee in poor light on a popular social networking site.

Party spokesman Manish Tewari said the Congress always believed in the freedom of right of expression granted by the Constitution which was intrinsic to the democratic ethos of the country.

He, however, added that he had no first hand knowledge of the incident and therefore it was inappropriate for making any sweeping judgement without understanding facts from the West Bengal unit of the party.

Congress is a junior partner in the West Bengal government headed by the Trinamool Congress chief while Ms. Banerjee’s party is the second largest constituent of the UPA at the Centre after Congress. In recent times, Trinamool has emerged as the most troublesome ally for the Congress at the Centre.

The cartoon by the Professor of Chemistry of Jadavpur University also involved Railway Minister Mukul Roy and former Railway Minister Dinesh Trivedi.

Police have said that Professor Ambikesh Mohapatra was arrested along with a neighbour residing in east Jadavpur for spreading derogatory messages against “respectable persons”.

The cartoon showed the Chief Minister and the Railway Minister exchanging dialogues from a popular Bengali film by Satyajit Ray which alluded to the replacement of Dinesh Trivedi by Mukul Roy as Railway Minister.