ABP Food Group has said its investigations into how some of its burgers came to be contain horse DNA remain focused on third-party suppliers from the Continent, despite reports over the weekend that the source of the DNA may not be imports after all.

Irish Taoiseach Enda Kenny was reported in the Irish media as saying he was “not satisfied” the Irish government had identified the source of the problem, following suggestions imported ingredients may not be to blame.

ABP said it was investigating all possible sources of the contamination but added “at this stage, the investigations remain centred on third-party ingredient suppliers from the Continent”.

The company, whose Silvercrest Foods plant has temporarily suspended all production pending the investigations, also reiterated it had never knowingly bought or processed horse meat, adding “the company is still shocked by a finding of 29% equine DNA in one burger sampled in the [Food Safety Authority of Ireland’s] survey.

To date, investigations into the contamination are believed to be focused on ingredients suppliers from Spain and the Netherlands.

A spokesman for the Dutch food safety authority NVWA confirmed it was carrying out its own investigations into the incident but said had not come to any conclusions yet. He said NVWA was unable to say when it was expecting results but added it would share any insights with “our colleagues in Ireland”.

Spanish regulator AESN said last week it was in permanent contact with the FSAI and stressed there was no concern about food safety.