Tests for horsemeat in processed meat products are being expanded, the Food Standards Agency has said.
Work will start next Monday to look at foodstuffs labelled as containing beef as a major ingredient.
That could include products such as minced meat, prepared meat such as seasoned kebabs, gelatine, beef dripping, stock cubes and steak.
Two types of product - raw minced beef and beef-based ready meals - are already being checked.
A total of 514 products will be surveyed altogether, the FSA said.
In the first phase of the its investigation, 224 samples of raw minced beef products including burgers, minced beef, beef sausage or meat balls, are being checked for horse and pork DNA.
In the second phase, which began on Thursday last week, 140 samples of beef-based ready-meals are being tested. The tests cover frozen, chilled or canned lasagne, chilli con carne, cottage pie, ravioli, cannelloni and spaghetti bolognese.
Those tests, to detect horse and pork DNA, will be complete by 22 February.
Under a third phase, 150 samples will be taken as part of a European Commission survey and checked for horse DNA. This phase will include products - yet to be decided by the FSA - labelled as containing beef as a major ingredient.
Work on this phase is scheduled to start the week beginning 25 February.
The sampling for the first two phases is being carried out by 28 local authorities, while sampling for the third phase will be allocated to other local authorities across the UK.
The FSA will publish all its results from the end of February and announce any action it is taking in April.
Mary Creagh MP, Labour's Shadow Environment Secretary, welcomed the move, saying: "Labour has been calling for the FSA to get faster results and test more products for weeks.
"With cubed steak, kebabs, stock cubes and gelatine among those new products to be tested there are indications that the horsemeat scandal could go even wider than previously thought.
"These new tests need to be done quickly - people want answers now."
Earlier, a food manufacturing company that supplies Whitbread with burgers said it was looking into the presence of horse DNA in one of its products.
Paragon Quality Food, near Doncaster, South Yorkshire, said it bought beef only from licensed and approved EU suppliers and had never knowingly bought or handled horsemeat products.
"All our records are available for scrutiny to our customers and [Food Standards Agency] officials," it said.
"This is a supply chain problem across Europe due to the adulteration of raw material by criminal elements. As a key beefburger manufacturer, the integrity of our product is paramount."
Whitbread - which owns Premier Inn, Beefeater Grill and Brewers Fayre restaurants - said on Friday it had found horse DNA in Paragon burgers and in lasagne from Brakes Brothers.
The House of Commons has withdrawn four Brakes beef products from its catering outlets while tests are carried out for horse DNA.
Beef and onion pie, steak and kidney pie, steak and kidney suet pudding and beef Italian meatballs were taken off cafe shelves.
Two of the products have tested negative for horse DNA and tests on the remaining two are continuing.
Meanwhile, Nestle, the world's biggest food company, has removed beef pasta meals from shelves in Italy and Spain after tests revealed traces of horse DNA.
Tests on its processed beef products sold in the UK and Ireland, consisting of seven Jenny Craig products and two Gerber baby food products, however, had confirmed there was not any horsemeat present, it said.
The UK's National Beef Association has blamed what it called the "bullying culture" retail buyers have used for decades for the presence of horsemeat in beef products.
National director Chris Mallon said the public and retailers were paying the price for "short-sighted, price-led purchasing tactics".
He said buyers had "adopted a bullying culture aimed exclusively at securing as much farm food as possible for as little cost as possible".
"The result is tortured supply chains that add so much unnecessary cost that short cuts on quality and traceability, and even cheating by some suppliers, (is) inevitable".
Buyers should take on high-quality British-farmed food instead, he said.