Controversial facial recognition equipment has been used for the first time in the country at a port in Yorkshire.
Humberside Police said early results from a two-day trial using a police database and existing CCTV cameras at King George Dock, in Hull, were positive and they would testing it further over three months this Autumn.
Serious crime gangs are among the 1,000 foot passengers who pass through the port every day and officers say it is merely automating a process which used to involve people in a booth looking at photographs of suspects.
However civil liberties groups have raised concerns over the creeping use of “highly invasive” technology which they said had been shown to be “dangerously inaccurate and potentially discriminatory.”
Two legal challenges have been made against police in south Wales and London on the grounds it is unregulated and violates privacy.
In the trial the software picked out three officers acting as “controls,” who mingled with passengers arriving on a P&O ferry on June 13 and leaving the following day.
It also looked for 100 suspects wanted for a variety of offences including burglary and drug trafficking, but no arrests were made.
Assistant chief constable Chris Noble said there had been no “false positives” - as happened at the June 2017 Champions League final in Cardiff, where the system erroneously flagged hundreds of innocent people as being suspicious or worthy of arrest.
Asked about civil liberties he said: “If some of these individuals are perpetrators of human trafficking or drugs trafficking this is technology that can identify them - in my view that is protecting the civil liberties of victims.”
The force said it will consult with civil liberties groups, among others. ACC Noble insisted there were already “clear legal parameters” in which the police work and images of those who did not flag up on the system would be immediately wiped.
If a check is needed they would be held for 30 days - and people can ask them to be removed.
However Corey Stoughton, Liberty’s Advocacy Director, said there should have been consultation before the trial.
She said: “Without their knowledge or consent, hundreds of innocent passengers going about their business have have had their faces scanned, compared and potentially stored by police, using a technology that’s been shown again and again to be dangerously inaccurate and potentially discriminatory.
“There’s no law or independent oversight covering police use of facial recognition and there’s been no parliamentary or public debate about its use.
“It makes our privacy rights meaningless and could have a chilling effect on our free speech and our protest rights - which is why Liberty is launching a legal challenge to its use in Cardiff.
“Humberside Police must remember they have a responsibility to protect locals’ fundamental rights as well as keep them safe.”
Andrew Petherbridge, a civil liberties lawyer, from Hudgell Solicitors, said he welcomed police using new technology, but it needed to be open to scrutiny.
He is representing an alleged rape victim in a civil claim against Humberside Police over losing a DVD recording of an interview she gave. The force was fined £130,000 over the data breach.
He said: “Police need to listen to the concerns - I see the impact when they get it wrong.
“People will say if there is nothing to hide, there is nothing to be concerned about, but it human nature that people will change their behaviour is they are under surveillance.
“If police start using this at lawful demonstrations will it put people off their democratic rights to protest?”