POLISH ingredients identified as the most likely source of the horse meat in Irish burgers have been used for almost a year.
Test results received over the weekend confirmed meat trimmings from Poland contained up to 20pc horsemeat whereas no Irish ingredients contained any horse DNA.
Burgers made with that ingredient had been found to contain up to 7pc horse DNA.
The news was welcomed by Agriculture Minister Simon Coveney, who said it was "in some ways a vindication of the Irish food industry".
He said that this problem "was effectively imported from another member state" and therefore "sends a very strong signal as to the strength of the regulatory regime".
It is now thought that the controversy was caused by a beef product made from low-value cuts and trimmings which was sourced from several slaughtering factories. It was imported in frozen blocks.
According to Mr Coveney it will now be up to the Polish authorities to investigate the plants concerned.
Here department officials are planning to take weekly samples from Silvercrest Foods for six months after its plant reopens.
The company is to undertake a radical overhaul of its Monaghan facility as it tries to retain lucrative contracts. Fastfood giant Burger King said it will consider shortly whether to resume sourcing its burgers from the plant.
Mr Coveney outlined a series of stringent measures to prevent a recurrence of the horsemeat crisis at the Larry Goodman-owned Silvercrest plant, which had threatened to damage Ireland's €2bn beef industry.
This included a new management team and ongoing departmental monitoring at Silvercrest with continual DNA testing.
The company said it had carried out a complete reorganisation and its chilled beef division ABP Ireland had taken direct control of Silvercrest, while its sister business Dalepak in the UK was being put under the control of ABP UK.
It is also expected to comply with a Department request to source all its beef for Silvercrest burgers from Britain and Ireland in future.