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".
More top news
A terminally ill five-year-old boy led out the England team at Wembley with his "best friend" Jermain Defoe.
It comes as the country faces a major migrant crisis with more than 62,000 stranded including outside the port of Piraeus.
Regime change has unleashed sectarian and tribal urges and is tearing the country apart.