UK retailer The Co-operative Group has become the second retailer to drop Irish meat supplier Silvercrest Foods after tests found traces of horse DNA in its burgers.

The retailer today (30 January) said tests for horse DNA in frozen own-brand burgers supplied by Silvercrest proved negative in 13 out of 17 samples.

However, in three samples, traces of less than 1% were found and, in one, the level was 17.7%.

“We pride ourselves on the quality of the products we sell, and we are taking this matter very seriously,” a spokesperson for The Co-op said. “Our decision to withdraw these products at the first opportunity and cease taking further product from this site, has proven to be the correct course of action.”

Tesco said this morning it would ditch Silvercrest as a supplier in the wake of the horse meat scandal. It also plans to introduce DNA tests on all its meat products.

The UK’s largest grocer was one of a number of retailers found earlier this month to be selling beef burgers containing horse meat DNA.

The burgers were supplied by three plants in the UK and Ireland owned by meat processor ABP Food Group, including Silvercrest in Ireland.

A spokesperson for Tesco confirmed today that it would still use ABP as a supplier and said only Silvercrest had been “delisted”.

The Silvercrest plant remains closed, ABP confirmed today. It has introduced new DNA tests across its business and said it would audit all its suppliers.

At the weekend, Irish agriculture officials said the horse DNA had been traced back to raw material from Poland.

ABP said on Saturday it was “relieved” the source of contamination had been found. It added it had “never knowingly purchased or traded in equine product”. The group has appointed a new management team at the Silvercrest plant and introduced its own new DNA tests.

ABP said today it “understood” Tesco’s decision to no longer use Silvercrest as a supplier. “We have let our customers down in this incident and we apologise for this,” it said. However, it declined to comment on The Co-op’s move.