Rumours and a malicious media and social media campaign have resulted in the Calcutta police losing the trust of the people, an angry police commissioner Vineet Goyal said on Thursday as his men fought pitched battles with mobs at RG Kar Medical College and Hospital.

He insisted that the police have done no wrong in the case of the rape and murder of the young doctor that has sparked massive outrage and which resulted in thousands hitting the streets to reclaim the night and demand justice.

“We have never said only one person is involved,” the commissioner said. “We have not shielded anybody.”

He said as a policeman he could not arrest anyone on the basis of rumours. He said rumours had been spread about a Mahapatra being connected to a political Mahapatra. He said the police have verified that the intern concerned comes from an ordinary family with no political connections.

“Rumours have been spread,” he said repeatedly. “That bones were broken, this was done, that was done. Unfortunately, that is not supported by the scientific evidence.”

He thundered: “We are a responsible force. [Rumours have been spread that] evidence is destroyed. What evidence has been destroyed? You can't destroy evidence just like that.”