The airline says more than 250,000 passengers have boarded US flights via facial recognition alone, and more than three million on domestic flights.

After clearing traditional check-in and security, passengers can then go on to board without presenting their passport or boarding pass again.

The technology is currently deployed on BA’s routes to and from Los Angeles, New York JFK and Orlando, where BA says it can board almost 240 customers in 10 minutes after becoming the first carrier to set up permanent facial recognition gates at the airport.

At Heathrow, meanwhile, BA is the first UK airline to use the tech on domestic flights, with all domestic departures from the airline’s Terminal 5 hub now boarded biometrical.

For international flights, self-service boarding gates have been installed at the terminal allowing passengers to board without assistance using just their boarding card.

BA says the move is the “first step” towards bringing biometric boarding to international flights from the UK.

Raoul Cooper, BA’s senior digital design manager, said: “The airport of the future will be built upon biometric technology, from check-in and baggage drops to security checks and boarding.

“These days, automation is a part of everyday life, as is biometric technology via our mobile phones. We’re working with our technology partners and the US government to explore how we can use this technology in new and innovative ways to give our customers the stress-free, easy airport experience they tell us they want, while ensuring security is always our top priority.”

BA pledged £50 million last October to roll out end-to-end biometric services from summer 2019.