For anyone who didn't know, the clue was in the very long queue that was forming behind the cashpoint.

The machine at the BP garage in Stretford, Manchester, had a malfunction that made it dispense double the amount requested by customers.

Word soon got around – and for five hours, it continued to pay out before someone contacted the Nationwide Building Society to report the fault. The company said yesterday it was disappointing that no one had reported the fault earlier.

The machine gave out £60 every time it was asked for £30, but gave away more cash in different multiples depending on the amount requested.

Some customers reportedly used several cards to withdraw money. The Nationwide said it appeared the employee of a firm it used to top up the machine had loaded the notes incorrectly.

A 33-year-old man, who benefited to the tune of £150 but did not want to be identified, said: "The banks have had enough off us so it's good to get a little back. My friend texted me about 2pm. I couldn't believe it. You had to wait a while because people were putting their cards in five and six times but it was well worth it."

At one point, 50 people were in the queue. Shan Cliff, 21, said: "Most people have taken out hundreds of pounds. No one's going to turn down free money. I don't know whether it will show in our accounts but it's their mistake not ours."

Legally it is up to the bank whether it attempts to identify every faulty transaction and reclaim any overpayment. However, in previous cases banks have simply written off their losses.

A spokeswoman for Nationwide said: "We can confirm there was a problem and the ATM has been taken out of action while the problem is investigated.

"It will be put back in place and ready for action for the weekend. Obviously, some people were deliberately using the machine to take money which doesn't belong to them and we were disappointed people didn't alert us to it earlier in the day.

"I can confirm there was a problem with a third party supplier incorrectly loading the machine. At this stage we are still investigating the problem but we will reserve the right to contact people on an individual basis regarding this matter."