The head of the Food Standards Agency (FSA) tells MPs that Irish authorities are sure "filler product" used in contaminated burgers was from Poland, as Tesco sacks its supplier.
FSA chief executive Catherine Brown told the commons environment committee that the contaminated meat was in the form of blocks of frozen filler product made up of a mixture of beef and horse offcuts. The Polish supplier had been in use for a year.
Ms Brown conceded that the FSA had not regarded horse meat contamination as a potential risk and when asked how the public could know if horse meat had not been in burgers "for months, if not years", she said: "it is possible... and that's why I'm saying that it's very important now that we get to the bottom of the Polish connection and the Irish investigation because it is possible that these burgers have been on sale in this country .. when the Polish get to the bottom of this we will hope to know whether it's likely that this has been going on for a year."
Also questioned by the committee, Health minister Anna Soubry suggested responsibility could be apportioned to a "genuine fault" with the supplier in Poland. "We don't know whether or not the Irish, the people that made the burgers, didn't themselves know that the meat coming in was in some way contaminated. We don't know that yet.
"So therefore it could be that there is a genuine fault in Poland with the particular supplier of this meat, either deliberately or not deliberately because they haven't been doing the right checks. And until we can establish all those facts we can't roll it back in order to find out where the responsibility lies."
Asked if the burgers posed a health risk, Ms Soubry said there was "no evidence at the moment that there has been any unsafe food produced".
Further supermarket apologies
Tesco, one of the supermarkets first caught up in the scandal, on Wednesday announced that it had sacked Silvercrest, one of its main suppliers, which had processed the contaminated meat at one of the biggest burger plants in Europe, in County Monaghan, Ireland.
A Tesco spokesperson said that Silvercrest had failed to source, as demanded, all ingredients from the UK and Ireland and had been dropped for "breach of trust".
Following its own investigation into how the contamination of its value burgers with horse meat had happened and remained undetected, Tesco said it would introduce a new DNA testing system designed to detect any "deviation from our high standards".
Tesco group technical director Tim Smith told the environment committee: "My reassurance to Tesco customers is pretty straightforward: the rigor, the surveillance, the quality checking, the auditing take no notice of whatever the price that that product is being sold at or the recipe."
A Co-operative spokeswoman said: "Whilst there are no safety issues involved, it is now apparent that some of the withdrawn products have not met the high standards we and our customers expect. We apologise for this."
"We specify that all meat in our frozen burgers should be 100% British but we now strongly believe that some of the meat used to produce these burgers came from outside the UK and was not British in origin, and as a result we have taken the decision to delist Silvercrest as a supplier with immediate effect."