Drones have been used to drop contraband into the grounds of Westgate prison, Wayne Caines, the national security minister, told MPs on Friday.

The unmanned aircraft were spotted by prison staff three times in recent weeks, with contraband subsequently taken by officers.

Mr Caines was speaking in the wake of no-fly zones imposed at the airport, the prison and at police headquarters in Prospect.

He said the Government had no plans to ban the mini-aircraft, and that the regulations for now would have no impact on kite-flying around Prospect, a popular area for the pastime.

The criminal code will be amended to include penalties, but Mr Caines said the ban had been put in place as an emergency measure.

At present, a fine of up to $4,000 is in place for breaches.

Drones have also encroached on the airport, where a no-fly zone of 2.3 miles was imposed earlier this month.

Mr Caines was optimistic that manufacturers of drones could be approached to programme the no-fly restrictions into their circuitry.

Westgate has also explored frequencies that could knock out drones, but the minister cautioned that a “blanket over the prison” to prevent the use of mobile phones by inmates had come with unintended consequences of blocking all signals.