Two of the suppliers embroiled in the horse meat burger scandal have said they believe they have traced the problem to Continental Europe.

Dalepak Foods and Silvercrest Foods – both subsidiaries of Anglo Beef Processors – said they had launched a full-scale investigation into “two Continental European third-party suppliers who are the suspected source of the product in question”. They declined to reveal further details or disclose the identity of the suppliers under investigation or which countries they are based in.

Liffey Meats, some of whose beef products also tested positive for horse DNA in a survey by the Food Standards Agency of Ireland, said it had found the source of the contamination and also suggested imports were to blame, although it did not say whether they were from the Continent. The company said in a statement: “The company believes it has identified the source of the contamination. […] The source of the contamination is imported ingredients and these will be replaced from other sources before production is resumed and customers are supplied.”

Liffey did not say what kinds of “ingredients” were involved, but there is speculation in the meat industry the horse DNA at all three companies could be connected to the use of binding agents in burgers.

Dalepak, Silvercrest and Liffey all stressed they were not involved in the processing of horse meat, thereby ruling out the horse DNA could have ended up in the burgers as a result of cross-contamination in their plants. The FSAI also found pork DNA in a number of beef products from a range of processors, which it said was likely to be the result of different animals being processed in the same plants.

The FSA in the UK has launched an urgent investigation into the scandal and is holding a meeting with industry representatives this afternoon (16 January). Tesco has withdrawn 26 products from Silvercrest Foods as a precaution.