The horse meat scandal continues to hit the headlines as retailers and suppliers attempt to restore consumer confidence. Retail Week looks at how events unfolded.

16 January - An investigation by food safety officials was launched to discover how beefburgers contaminated with horse meat were sold in supermarkets including Tesco, Iceland and Aldi. Tesco and Iceland sold the burgers in the UK while Dunnes Stores, Lidl and Aldi sold the meat in Ireland, where the Food Safety Authority of Ireland (FSAI) discovered that the burgers contained horse meat DNA.

25 January - Tesco apologised and launched an urgent investigation after burgers that had been withdrawn from sale as a result of the horse meat scandal were sold to the public. Its own-brand Free From burgers were sold at its store in Cowley, Oxfordshire despite an alert warning at the checkout that “this product has been withdrawn from sale”. Although the burger was not found to include horse meat, the grocer had decided to withdraw the line of burgers as a precaution.

30 January - Tesco delisted the supplier at the heart of the horse meat controversy and it revealed that it will introduce DNA testing checks to “set a new standard”. Asda and the Co-op followed suit, ditching supplier Silvercrest following the discovery of horse meat DNA in beef burgers. The supplier used meat in its products that did not come from the list of approved suppliers Tesco had provided. Irish authorities said the horse DNA had come from a raw material product used by an unnamed Polish supplier.

8 February - The Food Standards Agency called for UK food manufacturers to test all processed beef products after a third-party French supplier alerted manufacturer Findus about concerns that its beef lasagne product contained between 60% and 100% horse meat, fanning the flames of the crisis further.

11 February - Retailers agreed to a new testing regime following weekend crisis talks and were braced for further revelations as the scandal grew rapidly across Europe. Retailers including Tesco and Sainsbury’s met Environment Secretary Owen Paterson on the Saturday.

12 February - The Food Standards Agency (FSA) and police raided a slaughterhouse in Todmorden, West Yorkshire, and a meat firm near Aberystwyth as the horse meat scandal implicated UK companies for the first time. On the same day Waitrose said it had discovered pork DNA in beef meatballs.

14 FebruaryMorrisons reports soaring fresh beef sales after advertising the fact it has a transparent meat supply chain.

15 February – UK supermarkets hit back at government criticism that they “remained silent” over the scandal. Iceland said that all of its own-brand beef products were free of horse meat, while results from the FSA tests gave The Co-op, Morrisons, Tesco and Sainsbury’s the all-clear. Foodservice giant Whitbread finds horse meat in its products.

18 February – The major grocers met with Environment Secretary Owen Paterson to thrash out a plan to restore consumer confidence. Asda chief executive Andy Clarke deems the meeting “very positive”.

19 February – Food giant Nestlé finds traces of horse DNA in three products on sale in Spain, Italy and France.

21 February - Asda chief executive Andy Clarke vows to “leave no stone unturned” in the hunt for the culprits involved in the scandal.

22 February – Retailers breathe a sigh of relief after test results on processed beef published by the Food Standards Agency found no new products contained horse meat. Independent laboratories have now conducted 3,599 tests including 35 samples which contained horse meat.

25 FebruaryIkea withdraws meatballs from sale in UK stores after tests in the Czech Republic found traces of horse meat in a batch made in Sweden. The meatballs have been pulled from stores in 14 European countries including the UK, France and Portugal.

26 February - Kantar Worldpanel data for the four week to February 17 revealed frozen burger sales fell 43% while sales of frozen ready meals declined by 13%.

27 February - Environment secretary Owen Paterson tells the National Farmers’ Union conference in Birmingham that those responsible for the horse meat scandal will face the “full force of the law”. Tesco chief executive Philip Clarke has vowed to lead a transformation in the food industry and to increase the amount of British meat the retailer sells.

1 March - No horse DNA found in the latest round of tests on processed meat products sold in UK stores. Four beef products sold by restaurant Taco Bell and catering supplier Brakes were found to contain horse meat. Products already withdrawn by supplier Birds Eye were also found to contain horse meat.

12 March - Tesco apologises after finding horse meat in a meatloaf manufactured in Northern Ireland.

19 March - The Horsemeat Action Group is set up to seek compensation for consumers affected by the horse meat scandal.

21 March - It emerges that Asda pulled a Smart Price corned beef line on March 8 which Leicestershire County Council found 50% horse meat in.