Police Scotland may use drones to spy on suspects, a senior officer has admitted.

The force intends to spend around £100,000 on two off-the-shelf unmanned aerial vehicles (UAVs).

When the plan was revealed last month Police Scotland said they would mainly be used to search for missing people and support officers on the ground.

On Tuesday, assistant chief constable Nelson Telfer acknowledged the drones may also be used to carry out covert surveillance.

At a meeting of the Scottish Police Authority, the oversight body for Police Scotland, he said: "Whilst they're designed as an overt policing tool - it's important to highlight that's the intention of the initial deployment - they may well be used for covert surveillance in the extremis."

He said any covert surveillance would be regulated under the Regulation of Investigatory Powers (Scotland) Act 2000.

It allows organisations like the police and councils to spy on people with the intention of uncovering crime.

Police Scotland has been considering introducing UAVs since 2015 and has been working with Glasgow University to develop a custom drone design.

It has also partnered with University of the West of Scotland to create sensors like thermal cameras.

Mr Telfer said the custom drone could put Police Scotland "at the cutting edge".

He added: "Ordinarily they would be used for overt police work but it would seem ridiculous that if an attempt to save a life which would require covert authority would be precluded because we've said we're not going to use them for that.

"If it becomes a regular and sustained use we would bring that back [to the SPA] and make that visible."

Devon and Cornwall Police became the first UK force to trial the use of drones in 2015 and have deployed them at crime scenes and fatal collisions.

A drone was also used by Lochaber Mountain Rescue Team during the search for a couple killed by an avalanche on Ben Nevis last year.