Brazen career criminals apparently prey on stressed out or tired passengers caught in a backlog at peak times while waiting to be screened, The Sun reported.

A security guard, who has worked for one of London’s major airports for more than a decade, told the Daily Mail items were stolen from security trays on a daily basis.

He said thieves took anything from laptops to wallets and even once managed to make off with a widow’s bag containing her husband’s ashes.

The security officer, who did not want to be named, revealed in most cases, the culprits had purchased a seat on a cheap flight with the sole intention of getting into the security areas.

“They tend to be middle-aged men who work in groups,” the guard said.

“They prey on passengers in the early morning, when people are half-asleep, or at peak times when they’re stressed, and target families who are likely to be distracted by children.”

Despite immediately watching CCTV and contacting police after a complaint was made, he said charges often weren’t brought because passengers were in too much of a hurry to catch their flights.

He revealed pressure on security staff to meet targets at his London airport had only exacerbated the issue, as he likened conditions to a “cattle market”. Officers were told they must get each passenger through screening in under six minutes, to keep the airlines happy and also so people had more time to shop at duty-free.

“Until around eight years ago, passengers would be dealt with by one officer — now officers have to deal with four passengers at a time,” he said.

“The trays often emerge quicker than the person going through the body scanner. Passengers get caught in a backlog and there’s nobody to watch for thieves.”

It comes a month after a student had her $1760 laptop — containing important documents for her dissertation — stolen from a security tray at London City Airport.

Fernanda Ardiles, who had travelled back to see her parents in the capital for Easter, had got held up in long delays while her bag went through the scanner quicker than she did.

When she eventually reached the end of the conveyor belt she was horrified to discover her MacBook Air was missing.

She was left in even more shock when she reported it to staff only to be told they would contact her once they had reviewed the CCTV.

It meant Fernanda had to return to university in Utrecht, in the Netherlands, without the computer where her vital work was stored.

“After three days of emails I finally got hold of the terminal manager who said there was nothing he could do, but pass it on for investigation,” she told The Guardian.

“They have behaved as though this is a minor irritation, as though it is no big deal.”

This article originally appeared on The Sun and was reproduced with permission.