Tests are continuing for the salmonella strain that led to Cadbury recalling one million of its chocolate bars.
About 30 products are still being tested in a continuing investigation after contamination was detected from a leaking pipe at one of the company's main factories.
The discovery led to the company pulling seven of its most popular brands off shop shelves on Friday June 23.
The Food Standards Authority said over the weekend that it was continuing to take samples from the factory "to make sure nothing else is affected".
A spokeswoman said: "There may be other products affected. We can't rule it out because tests are ongoing."
Cadbury said testing was standard procedure following possible contamination, and no salmonella had been found.
A spokesman said: "We've conducted tens of thousands of tests over recent months, all of which have been negative."
Cadbury described the recall as a precautionary measure due to possible "minute traces" of salmonella in some products.
However, the Food Standards Agency said it had recommended the recall after deciding the traces of bacteria presented a health risk.
A spokeswoman said at the time: "We are advising people not to eat the products."
The contamination was caused by a leaking pipe at the firm's huge Marlbrook plant in Herefordshire, which 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 then transported to other sites at Bournville and Somerdale, near Bristol, to be blended with cocoa butter and turned into milk chocolate.
Cadbury came under fire for not reporting the salmonella traces earlier on, although the firm's senior executives insisted the chocolate bars were "perfectly safe".
The recalled products were: 250g Dairy Milk Turkish, Dairy Milk Caramel and Dairy Milk Mint bars, eight chunk Dairy Milk bars, 1kg Dairy Milk bars, 10p Freddo bars and 105g Dairy Milk Buttons Easter Eggs. ..SUPL: