(Adds comments on France, Belgium and the Netherlands)
By Andras Gergely and Kate Kelland
DUBLIN/LONDON, Dec 7 (Reuters) - Irish pig meat contaminated with toxic dioxins could have been exported to as many as 25 countries, including France and the Netherlands, Irish government officials said on Sunday.
The Irish government has recalled all domestic pork products from shops, restaurants and food processing plants because of contamination with dioxin -- which in some forms and concentrations, and with long exposure, can cause cancer and other health problems.
Neighbouring Britain, the main export market, has warned consumers not to eat any Irish pork products after tests revealed the contamination.
"We believe it's in the order of 20-25 countries. It's certainly less than 30," Chief Veterinary Officer Paddy Rogan told a news conference, speaking about how many countries could be affected, but he did not list all of them.
France and the Netherlands notified Ireland they had received contaminated shipments of meat or processed foods which later turned out to have originated in Ireland, while Belgium received contaminated by-products, officials said.
"They didn't contact us until we had gone public," Rogan said.
Authorities said 10 farms in Ireland and a further 9 farms in the British province of Northern Ireland had used a contaminated pig feed that prompted Dublin to announce the recall on Saturday.
Britain's Food Stands Agency, a government body tasked with protecting public health and consumer interests, said it was investigating whether any contaminated pork products had been distributed in the UK -- a major importer of Irish pig meat.
"The Food Standards Agency is today advising consumers not to eat pork or pork products, such as sausages, bacon, salami and ham, which are labelled as being from the Irish Republic or Northern Ireland," it said in a statement.
British supermarket group Asda, owned by U.S. retail giant Wal-Mart, said it was pulling all Irish pork products from its shelves.
RISKS LOW, CONSUMERS WORRY
The Irish government said on Saturday that laboratory tests of animal feed and pork fat samples confirmed the presence of dioxins, with toxins at 80-200 times the safe limits. Preliminary evidence indicated the problem was likely to have started in September of this year, it added.
The Irish Exporters Association said the total exports of pig meat and related added value products such as pizzas, pies and sandwiches containing pork was about 750 million euros ($950 million). It said 63 percent of this went to the UK.
Britain's FSA said it did "not believe there is significant risk to UK consumers."
The Irish Association of Pigmeat Processors said the contaminated pig feed came from one supplier and the source had been contained.
Experts also said the risk to consumers was low.
"These compounds take a long time to accumulate in the body, so a relatively short period of exposure would have little impact on the total body burden," said Professor Alan Boobis, toxicologist at Imperial College London.
"One would have to be exposed to high levels for a long period of time before there would be a health risk."
Irish officials compared the case to a contamination scare in Belgian poultry in 1999, which has not been found to have had any negative health effects. They added that pork products would return to the shelves within days.
The European Commission said Ireland had acted well and quickly in recalling all locally produced pork products.
But people in Dublin were worried.
Teresa Moran, 57, a careworker and mother of five, said: "I have two pieces of pork in the freezer and I'm afraid of my life to touch them. I don't know what we are going to do about the ham for Christmas. We'll just have to wait and see."
Ireland's Food Minister Trevor Sargent said the problem may originate with by-products of baking that are dried to be used as animal feed. The fuel used in the drying process should be a food-grade oil.
"We do have our suspicions this time that the oil being used was not food grade and therefore may have led to the contamination which has caused such a crisis throughout the industry but only affecting a small amount of pork." (Additional reporting by Carmel Crimmins in Dublin and Michael Kahn in London; Editing by Matthew Jones)