Kolkata, May 13 (IANS): In a jolt to the Mamata Banerjee government, the Calcutta High Court here Monday ordered the CBI to take over the probe into a Trinamool Congress worker's death allegedly in the custody of West Bengal Police.

Kazi Naseeruddin died in the custody of Dhaniakhali police station in Hooghly district Jan 19, after he was arrested the previous night.

A bench of Chief Justice Arun Mishra and Justice J.M. Bagchi directed the Criminal Investigation Department (CID) of the state police to hand over the case files to the Central Bureau of Investigation (CBI) within seven days.

A public interest litigation was filed in the court for the same. It was alleged that Naseeruddin's death was a "pre-planned" political murder. Congress leader Abdul Mannan had claimed that Naseeruddin had been in touch with the Congress to switch over to the party.

Naseeruddin was found lying dead outside the police station, which led to his supporters attacking the police station.

Following a complaint by Naseeruddin's wife Manoja Bibi, the CID which was investigating the case arrested three policemen.

Immediately after the incident, Trinamool legislator from the area, Ashima Patra had given a clean chit to the police saying the "death was due to natural causes".

Mannan accused the ruling Trinamool Congress of colluding with the police to hush up the matter.

The West Bengal Human Rights Commission (WBHRC) had ordered the state director general of police to conduct an inquiry into the incident.