The police, shaken by the enormity of the heist at a jewellery shop right in front of a police station here, have formed five teams to crack the case.

On Monday night, unknown persons decamped with jewellery, including 2 kg of diamonds, worth nearly Rs 11 crore from the jewellery shop Alukkas on Kumaran Road located in front of the Tirupur North police station.

The total closing stock of jewellery was 65 kg as on Monday night, according to police. Of this, the 25 kg in the locker was safe, police said.

Superintendent of police V. Balakrishnan said that the teams have been interrogating the employees and checking on the whereabouts of inhabitants in and around the area.

The whereabouts of former convicts are being checked to see how active they have been lately.

The special police teams have also been checking public places, including railway stations and bus stands. The SP said that the same modus operandi has been used in Vellore, Dharmapuri, Tiruchy and recently in Tirupur.

The teams formed have been inquiring about three persons who had repaired the air conditioners in the store for three days.

The person who had supplied the gas welding machine used to cut open the grilles in the ventilator of the jewellery shop has been detained for interrogation, according to sources.