The latest food supplier to be affected by the horsemeat scandal is the catering giant Sodexo, which supplies schools, care homes and the armed forces.
Earlier, Birds Eye withdrew three types of beef meals from sale, and Scotland banned the use of frozen burgers in schools and care homes.
Consumer Editor Chris Choi reports.
The catering at Ascot Racecourse, which hosts Royal Ascot - attended each year by the Queen - is run by Sodexo Prestige, according to the firm's website.
The company won four awards in last year's National Racecourse Catering Awards for its food.
A Sodexo spokeswoman would not confirm which of its sites had been supplied with the frozen products.
She also declined to name the supplier of the beef products which tested positive for horse DNA and would not say if it was a British or Irish manufacturer.
Sodexo describes itself as "the UK's largest event caterer and provider of corporate hospitality packages".
A processing plant in Ireland has been shut down after inspectors found it was exporting horse meat under a label in the Czech language which translated as beef.
B&F Meats, a small-scale deboning factory in Carrick-on-Suir, Co Tipperary, was selling mislabelled product to a customer in the Czech Republic through a trader based in the UK.
Officers from the Department of Agriculture's special investigations unit have been carrying out searches at the factory this afternoon.The department said B&F Meats had been approved to debone beef and horse meat.Mr Coveney described the factory as a "small scale" operation.
The Grocer, an industry magazine for the food, drink and grocery market, has claimed that an Irish meat plant has been suspended for labelling horsemeat as beef:
The Food Standards Agency released the latest tranche of test results submitted by the food industry today. They showed that out of 1,133 meat products checked, only six - including Sodexo's - were positive for horse.
In this second wave of tests, the products linked to samples showing horse DNA were:
- Sodexo's beef burgers, minced beef and halal minced beef
- Asda's chilled beef bolognese sauce
- Whitbread Group lasagne and beef burger
Earlier today Birds Eye withdrew three products from sale in the UK as a precaution after horsemeat was found in a product sold in Belgium.
Catering company Sodexo have withdrawn all frozen beef products from 2,300 outlets with immediate effect after Food Standards Agency horsemeat test results.