The Food Standards Agency (FSA) and police have raided a slaughterhouse in Todmorden, West Yorkshire, and a meat firm near Aberystwyth as the horse meat scandal implicates UK firms for the first time.

The FSA has suspended operations at both businesses – Peter Boddy Licensed Slaughterhouse in Todmorden and Farmbox Meats near Aberystwyth.

The West Yorkshire plant is understood to have supplied horse carcasses to the Aberystwyth firm, which were then allegedly sold on as beef for kebabs and burgers.

Boddy said he had been slaughtering horses from Ireland for three weeks, is fully licensed and is co-operating with the FSA.

He said: “As far as I am concerned I know nothing about the plant in West Yorkshire. I have never knowingly processed horse meat until three weeks ago.”

This is the first time suppliers in the UK have been implicated in the scandal, in which processed beef products have been found to contain horse meat. Suppliers in Poland, Romania and Sweden have all been connected to the practice as the details of the European meat supply chain have become convoluted.

European ministers from the Irish Republic, France, Romania, Luxembourg, Sweden and Poland, along with UK environment secretary Owen Paterson, are to meet in Brussels.

The UK’s largest grocers, consumer goods research firm IGD and Paterson met yesterday to further discuss the crisis. All processed beef products sold by the grocers have been ordered to be tested by the FSA in independent laboratories. These tests are likely to be extended to further meat products once the results are published on Friday.

Retailers are expected to begin testing non-beef processed meat products after the initial tests are concluded. A Tesco spokeswoman said: “We are currently testing all processed beef products for equine DNA. We are focusing on processed beef products as a priority but will be looking at other species are part of our wider programme.”

Separately, Waitrose has withdrawn its Essential British Frozen Beef Meatballs after pork was detected in two batches.

The upmarket grocer said last night it plans to build its own UK capability to produce a range of frozen meat products.

The new unit is planned to be operational within the next three months and will be based at Dovecote Park’s facility in North Yorkshire.

Dovecote Park has been exclusively supplying Waitrose since 1997 with fresh beef products including fresh burgers, steaks and joints.

IGD chief executive Joanne Denney-Finch said: “The food and grocery industry is genuinely as shocked about this issue as all of our shoppers and consumers.

“The food and grocery industry is passionate about its shoppers and consumers – maintaining their trust is paramount.