Calcutta police’s STF used two different number plates on an SUV, dragged a suspect 10ft down a crowded street into the vehicle and then crashed it, nearly botching what was to be a covert joint operation with Andhra Pradesh’s commandos to pick up Maoists.

The Greyhound commandos from the southern state have been left fuming at the performance of the city force on Wednesday.

“We had come to Calcutta with specific information and sought the STF’s help. The plan was to whisk away the suspects silently but that did not happen,” said a Greyhound officer.

The agencies engaged in anti-Maoist operations follow a standard procedure. They pick up “targets” quietly and detain them in secret places for prolonged interrogation before producing them in court. Though there is no legal provision for detention, it sometimes continues up to 10 days.

“Detention is crucial. We obtain information about key Maoist functionaries during this period and arrest them immediately. If Wednesday’s operation had remained covert, we could have picked up more Maoists, who were supposed to meet those we arrested. But now they have fled,” said the officer.

A spokesperson for STF said the members of the team did the best they could under the circumstances.

The five picked up from central Calcutta in the operation are central committee member Sadananda Ramakrishna from Andhra Pradesh, Dipak Kumar from Chhattisgarh and Sukumar Mondal, Shambhu Pal and Bapi Mudi from districts adjoining Calcutta.

Ramakrishna was the state secretary in Andhra Pradesh when the outfit used to operate under the banner of People’s War. After the party merged with Maoist Communist Centre in 2004, he became the central committee member of the new organisation, CPI (Maoist).

STF officers chose a Mahindra Bolero for the operation. “On College Street, four policemen dragged a suspect at least 10ft to the car. The car should have been stopped close to the suspect so that he could be dragged in without pedestrians noticing. But instead, everyone around saw him being forced into the car,” said an STF source.

The incident sparked rumours of an abduction.

That the Bolero had different number plates at the front and the back was noticed when it hit another car on SN Banerjee Road, “a silly mistake”, according to the source. The traffic policemen had to be briefed about the secret operation so that the joint team could leave the spot.

The Greyhound team was left with no option but to register a case with Jorasanko police station and produce all five suspects in court on Thursday, as mandated by the law.