High levels of harmful chemicals have been found in cod liver oil sold by two high streets shops.

The supplements sold by Superdrug and Holland & Barrett were found to have higher levels of dioxin and dioxin-like PCBs than others brands.

The Food Standards Agency (FSA) asked both the firms to remove the fish oil from sale.

It said the capsules contained more than twice the recommended daily intake.

Two batches

The affected products are:

• Superdrug Pure Cod Liver Oil, bottled 300ml, expiry April 2003; batch number 300909
• Holland & Barrett Pure Cod Liver Oil, bottled 250ml, expiry August 2002; Batch number LO229

Dioxins and PCBs are potentially cancer-causing chemicals which are present in the environment and food.

They are not harmful to health immediately but the concern is over the damage done by long-term exposure to high levels.

We think it's unlikely that any stocks of the relevant batches remain

Holland & Barrett

The FSA tested 33 samples of branded fish oil supplement on sale across the UK.

Most of the dioxin levels found were low, apart from the two recommended for withdrawal from sale.

New EU-wide dioxin limits come into force from 1 July and will be enforced by local authorities.

Safeguards

Dr Jon Bell, the FSA's deputy chief executive and head of food safety, said: "While there have been measurable improvements in dioxin levels in fish oil supplements, there is scope for additional action by the fish oil supplement industry to reduce levels still further.

"The agency has initiated discussions with retailers and industry about ways to continue to reduce levels of potentially harmful dioxins in fish oil supplements."

Both Holland & Barrett and Superdrug said they were taking the FSA's advice and removing the product from their shelves.

A spokeswoman for Holland & Barrett said the samples in question were bought between October 2000 and October 2001.

'Still beneficial'

"We think it's unlikely that any stocks of the relevant batches remain.

"Nevertheless, as a precautionary measure, we immediately implemented a recall from all our stores.

"We also carried out a general review of product labelling, particularly with reference to levels of recommended doses for children of different ages and adults."

The Health Supplements Information Service (HSIS), an independent information service established to provide balanced advice and guidance on the use of food supplements, welcomed the report.

But the organisation stressed that fish oil supplements were still beneficial.

Derek Shrimpton, nutritional advisor to the HSIS, said: "Fish oil supplements are taken in very small quantities and therefore greatly limit any exposure to dioxins and PCBs."