Michelle O'Neill said the burgers had been supplied to Eurest outlets that supply Greenmount and Loughry campuses.

BBC: Northern Ireland

David Bailey, a manager at Eurest, describes the pinball layout of food stands, designed so customers bounce between different concessions, collecting items as they go.

ECONOMIST: Contract catering: Carving up the industry | The

Ms O'Neill said Eurest's parent body, Compass, had withdrawn the burgers.

BBC: Northern Ireland

"CAFRE has a service contract with Eurest, a subsidiary of Compass, which commenced in August 2011, to provide catering across the three CAFRE campuses, " she said.

BBC: Northern Ireland

In her reply, the agriculture minister said burgers containing horsemeat had been supplied to the Eurest outlets at Greenmount and Loughry campuses of CAFRE (College for Agriculture, Food and Rural Enterprise).

BBC: Northern Ireland