South Wales Police deployed facial recognition technology in Cardiff this weekend, making multiple arrests using the controversial kit.

The force has been using an automated facial recognition (AFR) system since June last year, when it launched a pilot during the Champions League finals week.

In December, the police boasted about its success and announced that the trial would be extended until March 2018, after which there would be another evaluation.

The police uses AFR in two ways: a "static" version to cross-reference images of people of interest against a database of 500,000 custody images, and a real-time one comparing live CCTV feeds to arrest people in the moment.

The force rolled out the real-time version on Saturday, when Wales went up against Scotland in the opening match of the Six Nations rugby tournament. Project lead Scott Lloyd tweeted about the deployment throughout the day.

His tweets claimed the first identification and arrest had been made "within an hour". Another said a man arrested on a warrant was further arrested for having drugs on him.

Another male arrested on warrant as a result of the Automated Facial Recognition deployment in Cardiff City Centre they have been further arrested for being in possession of drugs. Nowhere to hide! #swpafr #swp pic.twitter.com/McPrduzfTa — Scott Lloyd (@Inspectorslloyd) February 3, 2018

Lloyd then bragged about another arrest being made as a result of AFR, which he said was a UK policing first.

A third person has been arrested using Automated Facial Recognition in Cardiff City Centre. It’s another UK Policing first! Positively identified from night club CCTV a month ago using the technology and located in Cardiff during today’s deployment. #swpafr #swp — Scott Lloyd (@Inspectorslloyd) February 3, 2018

However, the technology has come under fire from opponents who question its accuracy, citing the risk of discrimination against certain groups and false positives.

Forces have been tight-lipped about the number of false identifications: in its December review, the South Wales Police said only that there were positive matches in 191 cases, with 12 arrests, 50 charges and eight prison sentences handed out.

After the London Metropolitan Police used AFR at the most recent Notting Hill Carnival, there were reports of 35 false matches and one wrongful arrest – but the force said only that one person had been "identified" and "spoken to", denying the person had been arrested.

Campaigners have also voiced concerns about the fact innocent people's faces are being scanned against criminal databases, arguing this is edging the UK closer to a surveillance state.

"It is a great infringement of fans' rights," said Silkie Carlo, director of Big Brother Watch, adding that the police "have no clear basis" for using the tech.

"Thousands of innocent people will have their faces scanned against a database of half a million photos," she said.

The Greater London Assembly – the group elected to hold the mayor to account – has also called for greater caution. Last year it wrote to mayor Sadiq Khan saying there was a "strong case" for him to ask the Met to stop the trials.

The GLA said it was "extremely disappointing" that the work has been done with "so little public engagement" and "in the absence of a legislative framework and proper regulation or oversight".

That's because the police are going ahead with the with the work in spite of the fact the government has yet to publish its biometrics strategy, which should give guidance on AFR and the retention of innocent people's images.

We asked the South Wales Police for details of the number of arrests, false positives and subsequent charges from the technology's use over the weekend.

In response, a spokesperson said they wouldn't be able to make our deadline, but did point us to two puff pieces on YouTube about how great the tech is. ®