Calcutta: The state CID got a new chief on Saturday as Sanjoy Mukherjee took over as the additional director general in place of Rajesh Kumar.

Mukherjee was earlier the director of security.

The outgoing CID chief, Kumar, a 1990-batch officer, will now be the ADG, pollution control board. The change is being seen as the outcome of Kumar's perceived proximity to Mukul Roy during his posting in Delhi in the past few years, Nabanna sources said.

The government order was issued on Saturday afternoon, less than 24 hours after Roy, a former Trinamul Congress minister, joined the BJP.

Mukherjee, a 1989-batch officer who has been the Barrackpore commissioner, DG (fire and emergency services) and IG, CID (special), will take over as ADG (CID). His primary duty will be to monitor and supervise investigation of cases in Bengal police area.

Ashok Kumar Prasad, a 1998-batch IPS officer who was IG (personnel), will replace 1997-batch IPS officer Sib Shankar Dutta as IG CID-II. Dutta's new assignment will be as IG (organisation).

Several officers have been reshuffled in the Bidhannagar commissionerates, South 24-Parganas police, Siliguri commissionerate and the personnel department.