"There are five 'pods' and when one breaks down, they all break down," he said.
He said immigration officers had been able to accompany travellers through the scanners without an alarm being triggered, even though the booths are supposed to detect if more than one person enters at a time.
and for me by far the most significant issue:
"Up until the point of the official launch, it was rejecting 30 per cent of those who tried to get through it," the UKBA worker said.
"We believe they had to recalibrate it – essentially make it easier to get through the system."
Thread renamed to match Telegraph source