The horse DNA found in Ikea meatballs last week came from Poland, Ikea’s Swedish meatballs manufacturer Dafgard has claimed.

The company said it had traced the contamination in the meatballs to a Swedish supplier that “contracted two Polish abattoirs”. It did not name the abattoirs or the Swedish supplier that had bought raw material from Poland.

Dafgard had now handed the case over to the police and the Swedish National Food Administration, a spokesman for the company added.

A batch of Dafgard-made meatballs tested positive for horse DNA in the Czech Republic on 25 February, prompting the furniture chain to withdraw them from sale in more than 20 European countries (including the UK and Ireland) as well as stores in Hong Kong, Thailand and the Dominican Republic.

Two days later, Ikea also withdrew wiener sausages made by Dafgard from the UK, Ireland, France, Spain and Portugal as a precaution, but these went back on sale earlier this week after DNA tests on the sausages came back negative.

Dafgard’s pointing the finger at Poland comes after the Irish government announced at the end of January that it had traced the source of adulteration in frozen burgers made at ABP Food Group’s Silvercrest plant back to Poland. This was reiterated by ABP chief executive Paul Finnerty earlier this week, when he told the EFRA committee of MPs that extensive tests at Silvercrest had confirmed Poland was the source of the contamination.

Polish authorities initially said they had found no evidence that beef was being adulterated with horsemeat in Polish factories, but announced last week that trace amounts of horse DNA were found in beef samples taken from three Polish plants.

Reports from Germany have also suggested some German suppliers implicated in the horsemeat scandal sourced raw material from Poland.