Cadbury has said it is regularly testing its products

Seven of the company's brands were affected by the recall but the mix used in those products was the base ingredient in other confectionery.

The Food Standards Agency has said there might be further products which have been contaminated.

Cadbury said it was testing product lines four times a day.

A Food Standards Agency spokeswoman said: "We cannot rule out that other products may be affected."

Leaking pipe

Currently, the 250g Dairy Milk Turkish, Dairy Milk Caramel and Dairy Milk Mint bars, the Dairy Milk 8 chunk and the 1kg Dairy Milk bar are among the products affected.

Also included, are the 105g Dairy Milk Buttons Easter Egg and the Freddo bar.

Cadbury has blamed a leaking pipe at its Marlbrook plant, near Leominster, Herefordshire for the salmonella contamination.

The leak was discovered in January with samples sent to an independent laboratory where a rare strain of salmonella was identified.

No traces

Government watchdog the Health Protection Agency (HPA) confirmed the strain.

Cadbury officially informed the FSA of the possible contamination of the seven products on June 19.

The FSA said the crumb mixture, in which the salmonella strain was found, was used in a very large number of Cadbury products.

But Cadbury said that it had tested tens of thousands of products and found no traces of salmonella.

Purely precautionary

The firm stressed it was working closely with the FSA and environmental health officers.

Previously, Cadbury said the recall had been carried out "purely as a precautionary measure".

The factory at Marlbrook generates 97,000 tonnes of milk chocolate crumb every year.

It processes 180 million litres of fresh milk, 56,000 tonnes of sugar and 13,000 tonnes of cocoa liquor annually in the production process.

The crumb is transported to other sites at Bournville, near Birmingham, and Somerdale, near Bristol, to be blended with cocoa butter and turned into milk chocolate.