Kolkata police has arrested one of its sub-inspector Shankar Chakraborti for smuggling out ammunition from police armoury.

 Chakraborti was remanded to police custody for four days by a court on Tuesday.

 He had been selling ammunition to criminals for nearly two decades said a top police official.

 "He built up a racket to collect ammunition issued for practice firing at the camp. Probably, he used to collect the bullets from the trainees, who did not complete their quota of practice firing," he added. Chakraborti was selling a bullet for Rs. 100. The arrested SI who was working in the CID had a rapport with local criminals looking for ammunition.

 Chakraborty joined the West Bengal police as a constable in 1973. Later, for 11 years (he was posted at the police training camp in Nadia and was guarding the armoury.

 The police now suspects that other departmental staffs are also involved in the crime.

 "We are looking for other racketeers," said Supratim Sarkar, SP, North 24-Parganas.