FIRST Minister Nicola Sturgeon is to seek more information from Police Scotland about the force's use of controversial facial recognition software.

Her spokesman said she would be contacting the force "at official level" after she was quizzed on the issue during First Minister's Questions.

Willie Rennie, the Scottish Lib Dem leader, claimed the use of facial recognition technology to match CCTV images with mugshots stored on a huge UK-wide police database could infringe people's privacy.

Earlier this week the force revealed for the first time it was using the software to trawl the National Police Database, which contains 18 million images.

Responding to a freedom of information request, Police Scotland confirmed it had carried out searches on 440 occasions.

It also revealed it had uploaded 601,837 custody mugshots of 334,594 individuals to the database but stressed only images of those who were convicted were retained on the system.

Mr Rennie said: "There are strict rules on taking fingerprints and DNA to check against those databases, but the same rules do not apply to the photograph database.

"The concern is people's privacy if the police can take photographs at, say, football matches or political demonstrations to compare them to photographs with the database using this technology.

"Safeguards are in place for fingerprints and DNA.

"Does the First Minister think there are adequate safeguards covering photographs too?"

Ms Sturgeon replied: "When we look at that balance between the need to protect the public and the very important need to protect civil liberties, it strikes me that we have got it right in this case.

"But of course these things continue, always will continue, and rightly so, to be kept under review."

She added: "Perhaps most routinely will be images from CCTV cameras that will be used to try and identify people through images held on the police national database.

"I'm only speaking personally here, but if I or a member of my family was, for example, a victim of assault in the street and there was CCTV images of someone who there was a suspicion might be guilty of that, I would want that to be used to see if we could identify the perpetrator of that crime.

"So, let's not lose sight here of the purpose and objective of this - it is to apprehend and bring to justice criminals, and in my view that is good thing."

A Scottish Government spokesman later confirmed: "We will now contact Police Scotland at official level for more information."

The UK's independent Biometrics Commissioner Alastair MacGregor recently raised concerns about police forces using computer software which can match custody mugshots with faces trawled from CCTV images of crimes without a "proper and effective regulatory regime".