Thieves spent six months digging a tunnel to steal money from an automatic teller machine -- but probably only got away with £6,000, British officials said.

The gang excavated the 100-foot (30-metre) long tunnel under a car park and part of a video shop in Manchester, northwest England, in order to raid the cash machine inside the building, police said.

They installed lighting and roof supports, and were also believed to have drilled tiny holes into the floor of the store through which they poked telescopic cameras to check their progress.

"In all my years of service, I have never seen anything quite as elaborate as this," Detective Ian Shore said.

"These people had obviously spent a long time plotting this crime."

But a source at the store told Britain's domestic Press Association news agency that there was only just over £6,000 in the machine.

"It was only when security came to fill the machine back up that they discovered the hole" in early this month, the source said.

A similar attempt was foiled in 2007, police said.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.