Claims that Cadbury is set to be prosecuted over last year's salmonella scare were denied by the chocolate manufacturer and the Midland councils investigating the company yesterday.

Birmingham City Council, which would jointly launch a potential prosecution under environmental health laws, said it is yet to conclude its initial investigation into the health alert.

A decision on whether to bring charges against Cadbury would not be made until that inquiry is completed, a spokesman said.

An official from Cadbury said the company had not been notified of any action concerning breaches of food safety rules being launched.

Herefordshire Council’s inquiry is focused on the factory at the centre of a salmonella scare.

Up to 10 staff have scoured the Marlbrook production site since the investigation launched last summer. Herefordshire Council’s head of environmental health and trading standards, Andrew Tector, yesterday said the probe should finish in March.

Birmingham City Council, which is thought to be the lead agency in the investigation, is still carrying out a separate inquiry at Cadbury’s headquarters in Bournville.

The two local authorities have not yet decided whether they would bring any potential legal action together, or separately.

Mr Tector said: "We hope that by March we will be in a position to make a decision on the outcome of the investigation. We are looking at the plant where the chocolate crumb is produced that appeared to be contaminated."

Birmingham City Council wouldn’t say when its investigation was due to end. A spokesman said that the inquiry had been extended because of its complexity.

He added: "In fairness to all parties we are taking every possible step to ensure our investigation is as fair and thorough as possible.

"In order to do this we have conducted hundreds of detailed scientific tests and are continuing to interview key witnesses from all over the country.

"Until the investigation is complete we are unable to speculate on the possible outcomes."

Cadbury was forced to recall a million chocolate bars after last summer’s salmonella scare.

The chocolate giant predicted the recall would cost the firm at least #20 million.

The Health Protection Agency branded Cadbury’s chocolate the most likely cause of a salmonella outbreak which affected more than 30 people last year.

According to reports, officials involved with the two investigations are set to announce a prosecution before the end of the month.

It has been claimed that Cadbury will face charges of producing food unfit for human consumption, and will also face action under European laws for failing to inform the authorities in good time about the problem.

The company has never admitted liability for the outbreak, but its chief executive Todd Stitzer, said in the summer he was "truly sorry" for what happened.