The Kolkata police has sought the help of Interpol to find the missing monkeys from the Alipore Zoo, and announced a reward of Rs 50,000 for any person who gives credible information about the theft. High level state functionaries - such as Chief Secretary Ashok Mohan Chakraborty, Home Secretary Ardhendu Sen and Police Commissioner Gautam Mohan Chakraborty - took stock of the situation visiting the zoo on Thursday.

The Chief Secretary said: "We have requested the Interpol to help the police if they have any specific data about the theft. We have asked the forest department and the zoo authorities to appoint a new security agency in five days."

The government will soon appoint a new director and assistant director of divisional forest officer rank, besides appointing a high-ranking police official or a retired Army official as a security officer, in order to avoid such happenings in future.

Meanwhile, the government has arrested Ashok Parui, a staffer of the Alipore Zoo, who is supposedly not co-operating with the investigating team.

DD Chief, Jawed Shamim said: "Parui is changing his statement all the time. We cannot be strict with him as he is suffering from a cardiac ailment. If some untoward things happen while in custody, we will be pulled up by the National Human Rights Commission."