Environmental health officers said the kitchen at Riverside Hotel, in Mill Street, Mildenhall, was one of the worst they had seen when they carried out a routine inspection on January 24 last year, leading them to close the restaurant overnight until the catalogue of problems were rectified.

Photographs of the kitchen were shown to magistrates at Bury St Edmunds, where the company, Oxford Hotels and Inns, was prosecuted by Forest Heath Council and admitted six food hygiene offences and one charge of selling unsafe food.

In addition to the fines, the company was ordered to pay £8,000 costs to the council.

Prosecuting, Ian de Prez said district council inspectors found a dirty frying pan on the floor, mouldy food in the fridge and lamb shanks, raw fish and cream left uncovered without labels or dates.

They also found clean pans stored on a dirty surface next to a bin with no lid, grease and dirt in the oven and sludge on the floor where a drain was blocked – while an investigation found one employee did not hold a basic food hygiene certificate, he said.

Mitigating, Neil Davies said the hotel's manager, head chef and area director – who were sacked following an internal investigation – failed to implement the firm's food safety policies, although there was no evidence customers had eaten or been harmed by unsafe food.

He said the firm bought the business in 2005 believing all staff were trained, and said senior managers resolved the problems once they knew of them.

"These were not deliberate breaches and it's a not a case of profit ahead of safety," Mr Davis said.

"The company regards it as an entirely unacceptable state of affairs and one which has caused significant embarrassment."

Magistrates fined the company £12,000 for placing unsafe food on the market and £3,000 for each of the six other offences, ordering it to pay £8,000 in costs and a £15 victim surcharge.

After the hearing, Forest Heath's principal environmental health officer Tom Wright said: "This was probably one of the worst cases we have ever come across, and we are very pleased with the level of fine awarded."

In a statement, the company said it accepted the court's decision, adding that it concerned "an isolated incident almost two years ago caused by a local management failing".

Following the hearing, Mark Edwards, managing director of Oxford Hotels and Inns, said: "We accept the decision made by the court.

"We would like to stress to our customers that this was an isolated incident almost two years ago caused by a local management failing.