Mice droppings were found at the food kiosks and executive dining areas inside Leicester City's King Power stadium.
During one inspection by environmental health officers, a dead mouse was found in a store area and a mouse was seen running about in a food kiosk, Leicester magistrates were told.
Yesterday, Compass Contract Services (UK) Ltd, which runs catering at the stadium, was landed with a £16,000 bill after pleading guilty to three charges of contravening food hygiene regulations.
Prosecutor Nicki Agalamanyi told the court how 10 of the 16 food kiosks inside the ground had evidence of mouse activity during a routine inspection by Leicester City Council environmental health officers on March 3 last year.
Miss Agalamanyi said a pest control company employed by the football club to monitor the site had already made 52 visits to the ground between January 2011 and February last year. She said mouse activity was found on 35 of those visits to the stadium and various action plans were suggested.
Miss Agalamanyi said city environmental health officers then made eight inspections at the ground between March 3 and April 17. Despite action plans being drawn up and cleaning done, when officers visited on April 17 there was still lots of evidence of mouse activity.
She said: "There were dropping in the Great Hall, the Walkers Hall and there were droppings on napkins on shelves in the Weller Lounge.
"There was a dead mouse in a cooking oil filter in a ground storage area."
Birmingham-based Compass admitted not putting adequate procedures in place to control pests at the stadium.
The firm also pleaded guilty to not ensuring that the premises were adequately protected against pests.
The company admitted that food and materials stored in kiosks were not kept in appropriate conditions designed to protect them from contamination from pests.
Claire Morrissey, representing Compass, said there had been a breakdown in communication within the company and with Leicester City FC. She said: "This company is the largest provider of contract catering in the UK and Ireland and employs more than 50,000 people. There were policies in place to deal with these issues but they were not followed. The company apologises for this. A very limited risk was presented to the public. This is not the case where the whole stadium was overrun by mice."
She said more stringent daily checks had been put in place to try to prevent a repeat of the breaches.
Compass was fined £8,000 with £8,245 costs.
Chairman of the bench Tony Whitmore said: "The level of contamination was not as bad as it sounded but it affected a lot of outlets. I am concerned by the lack of activity by a large and experienced company. Management are there to manage."
A spokeswoman for Leicester City Council said: "Compass catering has co-operated fully with the council in our investigation into the incident and hygiene standards at the stadium have significantly improved since March 2012.
"On the last inspection in March 2013, the premises were awarded the top rating under the food hygiene rating of five, which is the highest mark available."
After the case, a Leicester City Football Club spokesman said: "We are aware of the situation that unfolded 14 months ago with our stadium catering contractors, Compass Group, and the steps that have been taken to rectify the issues arising, including a change of management in charge of stadium catering operations.
"We sought assurances that health and safety procedures would be thoroughly reviewed and, following the award of a five star health and safety rating from the environmental health officers earlier this year, are confident these matters have been resolved."
