Sales of Cadbury chocolate in leading supermarkets are already back on track after a slump following a salmonella scare.

Last month The Grocer revealed that sales of the company's products had dipped by 25% in two leading supermarkets, after a product recall prompted by the discovery of salmonella at a Cadbury factory in Marlbrook. But now sources at the retailers say they are back to pre-recall levels.

"Sales of Cadbury chocolate are back to exactly where they were before the salmonella outbreak," one source at a leading supermarket said. "The change in weather may have something to do with it as the whole sector is up in terms of sales, but Cadbury is exactly where it was before." A rival supermarket also said its Cadbury sales were back to normal.

However Cadbury's joy may be short-lived. This week Birmingham City Council confirmed to The Grocer that it expects its investigation into the ­salmonella scare to be ­completed in three months, when a decision will be made as to whether Cadbury will be prosecuted.

But John Allert, chief executive of brand consultancy firm Interbrand, said that even if Cadbury was prosecuted, the public would soon forget about the incident.

"It depends how Cadbury responds to any prosecution or fine," he said. "If they are prosecuted I think it will feel to some people like justice has been done. Cadbury will be looking to make a fresh start to repair any damage.

"I think by the end of this calendar year it will probably be a distant memory for Cadbury and for people who love the brand."

Earlier this month Cadbury revealed the product recall had cost £20m and said it was spending an extra £7m on advertising.

Meanwhile, this week Cadbury said that its new line, Dairy Milk Melts, would be available from 25 September and will be priced at £1.19.

The company will spend £2m marketing the product with Coronation Street TV sponsorship, PR activity and sampling.