A mix-up by suppliers led to motorists at a forecourt in the West Midlands putting the wrong fuel in their tanks.

Petrol was pumped into two diesel supply tanks at the Morrisons site in Kingswinford. One customer was only alerted when his diesel card would not work when he went to pay.

The two pumps carried on pumping the wrong fuel for about an hour but Morrisons said 12 vehicles were affected.

A spokesman for Morrisons said: "As soon as we were made aware of the issue, the tanks were shut down and the problem has been investigated.”

Anyone affected was told to contact Morrisons’ customer services or insurance department to pursue a claim.

It’s a major embarrassment for the supermarket chain as a similar thing happened at the Morrisons in Tavistock in Devon in 2008 and Tiverton in Devon last year – both incidents had unleaded pumps dispensing diesel.