The West Bengal CID on Tuesday arrested a state police officer for alleged involvement in an extortion case in West Midnapore district, a senior CID official said.

“The CID team arrested sub-inspector Rajsekhar Pain of West Midnapore district in connection with a complaint relating to misappropriation of Rs 45 lakh from a local businessman named Eunus Ali,” Deputy Inspector General, CID, Nishad Parvez said in a release.

According to sources close to CID, raids were conducted in the house of the officer for the last few days and a large amount of unaccounted cash was seized.

“The arrest was made observing all legal formalities. He will be produced before court on Wednesday,” Parvez said.

The sleuths have previously raided the houses of various police officers in the district in relation to a separate extortion case and arrested two officers including the former Officer in-Charge and circle inspector of Ghatal region, thought to be close to former district police chief Bharati Ghosh.

Pain, who was officer in charge of Kharagpur police station when the incident of alleged extortion took place, has also worked under Ghosh.

The CID has already issued an arrest warrant against Ghosh and her former security guard and seized more than Rs 2.4 crore in cash and several important government documents after raiding a number of flats in an apartment in Kolkata’s Madurdaha area — suspected to be owned by her.

CID teams have fanned outside the state to conduct search operations and take legal action against the other suspects and accused in the cases of extortion.

The raids started in response to a case of extortion and criminal conspiracy lodged in West Midnapore district’s Daspur on 1 February after a gold trader named Chandan Majhi complained against some police officers thought to be close to former SP Ghosh.

Ghosh, once a favourite of Chief Minister Mamata Banerjee, reportedly fell from grace and sought voluntary retirement after being transferred to a less significant post as commandant of the State Armed Police’s Third Battalion. Her application was accepted.