FISH and chip shops have been caught serving up haddock disguised as cod.

Worcestershire County Council and Malvern Hills District Council were two of the 52 local authorities that collected samples from chip shops, restaurants and pubs for an investigation into the type of fish being served up to customers.

The Food Standands Agency survey, which was published this month, revealed that 12 per cent of fish and chip shops replaced cod with a cheaper alternative of haddock without telling the customer.

Out of 380 samples collected between October 2007 and February 2008 and tested at five laboratories, including the Worcestershire Scientific Services unit in Stourport-on- Severn, 38 had been described incorrectly on the menu.

No problems were found in Worcestershire in the national survey but trading standards officers recently launched investigations after three samples of cod were found to be panga fish.

The report said that as commercial fish stocks across Europe have depleted the temptation to substitute more expensive fish with less expensive species has increased.

It did not name the establishments guilty of misleading customers but said the authorities have taken action where necessary.