The horse meat contamination scandal is “almost certainly” the result of criminal behaviour, farming minister David Heath has suggested.

During a debate in the House of Commons earlier today, Heath said: “It appears that it is not simply a labelling error. We are almost certainly talking about real criminality.”

His remarks seemed to suggest Heath had already judged criminal behaviour to be the most probable explanation for horse DNA being found in a number of burger products sold in the UK and Ireland, but Defra this afternoon stressed no final assessment had been made and investigations were still continuing.

Indeed, at other points in the debate, Heath used more cautious language, saying “we are investigating very fully and there may well be criminal prosecutions as a consequence” and that the findings from Ireland “may lead to criminal proceedings”.

This was echoed by Defra, which stressed criminal prosecutions “may” – as opposed to probably will – happen as a result of the scandal. “We are awaiting results of the investigations,” a spokeswoman said.

During the House of Commons debate, Heath also urged MPs not to “talk down” the British food industry. “That something has been discovered in Ireland that is serious and may lead to criminal proceedings does not undermine the serious efforts that are taken by retailers, processors and producers in this country to ensure traceability and the standard of the food that is available to consumers,” he said.  “It is quite wrong to extrapolate from that and say, ‘This is common across the whole of the food industry.’ That would be a mistake, and it would undermine an important industry.”