By NICK McDERMOTT

Last updated at 15:04 20 March 2008

Once the word was out, there was no stopping them. Within minutes of one lucky customer finding out that the cash machine at his local supermarket was giving out double the requested withdrawal, the news spread like wildfire.

Customers popping down to their Sainsbury's Local store for a few basics got in on the act - and they were soon joined by hundreds of others as they alerted family and friends to the ultimate supermarket bargain.

At one stage, the queue for the cash machine was a 100-strong - with many making multiple withdrawals in the hope they will not be traced and asked to repay the cash.

Scroll down for more ...

"It was really funny seeing all those people trying to get one over on the banks," said a witness.

"They were walking away with huge wads of cash and big smiles on their faces.

"They were ringing their mates and telling them to get down quickly. It makes up for all the bank charges, I guess. I hope they don't have to pay it back."

The crowd began gathering at the store in Hull at around 5pm on Tuesday and finally dispersed at 8pm when the faulty ATM ran out of notes.

Scroll down for more ...

One man, who did not wish to be named, said: "I was driving past when I saw a huge queue at the cash machine.

"I parked up and learned that it was paying out double. I joined the queue and when I finally got to the front, I drew out £200, but it gave me £400.

"The statement said I only drew out £200. I don't know whether I will have to pay it back."

Not everyone was so lucky. Taxi driver David Mellors, 37, pulled up too late and by the time he reached the front of the queue, the machine had run out of notes.

The father-of-seven said: "I was disappointed. It was the ultimate buy one, get one free sale and I missed out."

A spokesman for Sainsbury's said the cash machine was run by a private company. She declined to give the company's name and said it was unable to comment.

Asked how much money Sainsbury's believes was lost from the machine, she replied: "We do not know and we would not give out that kind of information."

She added: "It ran out of money at 8pm. The police came to see the machine and the matter is under investigation."

Most debit cards have a daily cash withdrawal limit of £300 - meaning that those lucky enough to use the haywire machine were able to take out a maximum of £600.

Whether they will get to keep it is another matter. The cash machine operator will have a record of all withdrawals made on the day.

It is then up to the discretion of the customers' banks whether or not they seek to trace each one and attempt to reclaim any overpayment.

On similar previous occasions, some banks have chosen to write off the money rather than pursue a large number of claims.

And there may be many more potential claims to be chased after unconfirmed reports suggested that other machines were also hit by the same fault.

The Sainsbury's spokesman said: "We think a number of cash machines outside supermarkets in Hull experienced similar problems."