A woman collapsed in a queue after all passport e-gates stopped working during chaotic scenes at Heathrow Airport this morning.
The scanners - which are operated by Border Force officials - briefly went down in Terminal 3, leaving hundreds of passengers waiting in lengthy lines as they came off overnight flights.
A spokesperson for the UK's largest airport said colleagues were on hand to help during the delay, and that the machines are now back up and running.
Heathrow confirmed the woman fainted, but the cause is not currently known. It is understood she collapsed after the queue started moving, and had taken a long flight beforehand.
Passengers stuck in the hold-up took to social media, sharing pictures from inside the crowded terminal.
One person wrote: "The last thing someone needs after a 8 hour flight is what feels like an 8 hour winding queue at border control.
"No idea why the 25+ e-gates aren’t being used."
A Heathrow Airport spokesperson replied to the tweet: "We appreciate that this must have been frustrating.
"The Immigration process and operation of the e-gates is the responsibility of Border Force, so whilst we have logged your feedback internally and are monitoring the situation."
And BBC journalist Michael Cowan posted: "Absolute chaos at Heathrow this morning - none of @UKBorder biometric scanners working - not one- thousands of people waiting off long overnight flights - woman collapsed in queue - horrendous."
A Home Office spokesperson told the Mirror: "This morning a technical issue affected eGates at Heathrow Terminal 3. The issue was quickly identified and has now been resolved.
"We have been working hard to minimise disruption, with most border control queue times no longer than 30 minutes. We apologise to all passengers for the inconvenience caused.”
An airport spokesperson added: "Earlier this morning there was an issue impacting the e-gates in T3, which are staffed and operated by Border Force.
"Our teams worked closely with Border Force to find a solution as quickly as possible and they are now fully operational again.
"The processing and resourcing of the Border is the responsibility of the Home Office. We apologise for any impact on passenger journeys."
The delay comes after Heathrow revealed it managed to turn a heavy £1.4 billion loss in the first three quarters of last year into a £643 million profit this year.
Revenue grew 200 per cent to £2.1 billion in the same period.
Heathrow said it needs to build back its systems so it can meet demand at peak times. This will involve hiring 25,000 new staff which is "a huge logistical challenge".
There were also signs that passenger numbers were improving. In September, 5.8 million passengers chose the airport, just 15 per cent below 2019 levels and the highest since the start of the pandemic.
Chief executive John Holland-Kaye said: "We can be proud that everyone at Heathrow pulled together to serve consumers this summer - ensuring 18 million people got away on their journeys, more than any other airport in Europe, with the vast majority experiencing good service.
"We have lifted the summer cap and are working with airlines and their ground handlers to get back to full capacity at peak times as soon as possible."
