A SALMONELLA outbreak that left dozens of people ill will cost Cadbury at least £20 million, it emerged yesterday. More than a million chocolate bars were cleared from shop shelves in June after the discovery of the bacteria at one of the firm's main factories.

Cadbury Schweppes said it faced the multi-million-pound bill to cover the cost of the recall, advertising and improvements to its manufacturing operation. It estimated it lost revenues of £5 million in the week after the recall, with chocolate sales since then about 14 per cent lower than last year.

Health experts say Cadbury products were the most likely cause of a salmonella outbreak across the UK, involving the rare strain known as Salmonella montevideo. Up to 46 of the 65 cases reported to officials between March and July could be linked to its products, the Health Protection Agency said.

In Scotland, there were ten cases of Salmonella montevideo in the first half of this year, compared with two during the same period last year. There have been no cases since the end of June. John Cowden, of Health Protection Scotland, confirmed the ten cases and said: "These may have been due to the consumption of Cadbury's chocolate, but this has not been proved."

Several people struck by the salmonella bug have already sought legal advice. Catherine Henderson, 62, from Larne, County Antrim, has threatened to sue Cadbury after coming down with the illness, which can cause diarrhoea, vomiting, fever, chills and headache. Her law firm, Irwin Mitchell, said other apparent victims had also come to them. Sallie Booth, a partner with the firm, said: "We can confirm that we are currently investigating the most likely source of their exposure."

Cadbury said it was not aware of any legal action against the company. But Todd Stitzer, its chief executive, confirmed that the company had received 700 complaints from customers since the outbreak, including more than 50 from people suffering illness.

It has apologised for the outbreak, which has been blamed on a leaking pipe at a factory in Herefordshire in January. The Food Standards Agency has launched an investigation into why it took Cadbury six months to report the contamination. Mr Stitzer said the £20 million cost of the recall did not take account of the loss of sales through damage to the brand. He said: "It is very difficult to quantify that."

The company said sales generally dropped during periods of hot weather. Earlier this week, it emerged that Cadbury's sales could have slumped by 25 per cent since the salmonella scare.

Despite the continued bad publicity, analysts predicted the scare would not affect the company in the long term.

William Grobel, of Intangible Business, a brand valuation consultancy, said: "The salmonella incident was an isolated blip in one market that has now been resolved.

"There are unlikely to be any long-term repercussions - investors have responded positively; consumers are still buying products."

However, some analysts have forecast the total cost of the outbreak will reach as much as £40 million because of damage to the brand and lower sales.

Yesterday, Cadbury launched a £5 million marketing campaign, including the return of advertising on the ITV soap Coronation Street - which was suspended following the recall in June - as it looked to "rebuild confidence" in its chocolate.