The trial was considered a success, but it has come under fire from privacy advocates, the BBC reports.

Trials: Over six weeks in December and January, 770 visitors at a prison in Yorkshire, England, had their faces scanned to check if they were using fake identifies or repeatedly visiting different prisoners. Some visitors turned back after learning the software was being used.

A growing problem: More than 23,000 drug packages and mobile phones were seized by prison staff last year, an increase of almost 4,000 from the previous year. The Ministry of Justice said it had found that prison visits were a particularly common way to smuggle contraband in.

Controversial: Campaign group Big Brother Watch has accused the government of taking an “experimental approach to human rights.” A spokesperson told The Independent it was trying to gain public approval for face recognition technology in a “low-rights environment” before trying to introduce it more widely. The police in the UK have also been testing the technology in recent months.  

Regulation: There are growing calls, especially in the US, for face recognition technology to be more closely monitored and regulated. Even Amazon, which has been criticized for suppying the technology to police, joined in with its own call for regulation last month

Next steps: Government ministers in the UK a success are planning to deploy face recognition more widely across the country, according to the BBC.

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