Approved supplier Welsh Bros Foods confirmed a sample of its frozen minced beef has 'potentially tested positive' for above 1% horsemeat.
Wholesaler Castell Howell have contacted customers after a 'possible contamination' of cottage pies.
The Welsh Government says it is working with the police to ensure allegations of horse meat at a plant in west Wales are dealt with.
The Food Standards Agency say that burgers' sold in Gwynedd have been withdrawn from sale after they were found to contain horse DNA.
The burgers were made at the Burger Manufacturing Company (BMC) in Builth Wells that previously tested positive for horsemeat.
In a statement on their website, the FSA said that samples taken from products purchased at Nefyn Pizza & Kebab House in Gwynedd were found to contain "horse DNA at or above the 1% threshold for reporting."
Last month the FSA announced it had ended its investigation at BMC, as further tests revealed that the presence of horse DNA below 1%.
The FSA says that the product was not found to contain the veterinary drug bute or pig DNA.
I am today pleased to announce that the testing programme has concluded and of the 200 samples checked by our independent laboratory for the presence of equine (horse) protein, all results show them to be clear of any such contamination. Halal products also tested returned clear.
– Ashley Govier, Cabinet Member, Environment
We have moved swiftly to address issues identified in order to reinforce the traceability within our procurement protocols.
We are also working to ensure that these processes are extended to any other services that use our premises such as after schools clubs and are currently carrying out exercises to enable this.
I am also, pleased to announce that our bid into the collaboration fund has been accepted which will mean an investment of £750k over the next 3 years to help collaborate, rebuild and strengthen our regulatory service.
Cardiff Council say they've found no traces of horsemeat contamination in two hundred samples they sent for testing at the beginning of February.
Their programme of testing involved schools, care homes and council-run food outlets in the wake of the horsemeat scandal.
The Food Standards Agency says it has ended a horsemeat contamination investigation at The Burger Manufacturing Company in Builth Wells, as further tests have revealed that the presence of horse DNA is at a level below 1 percent.
The solicitor acting on behalf of the owner of Farmbox Meats near Aberystwyth has told ITV News that he is pleased by the decision of the Food Standards Agency to lift restrictions against the company.
– Aled Owen, Mr Raw-Rees' solicitor
My client has cooperated fully with with the FSA and has satisfied them that there is no material reason to keep the plant shut.
Mr Raw-Rees is pleased with the outcome and will continue to cooperate with the FSA as he always has.
He would like to thank friends, family, customers and neighbours for their support in this difficult time.
– Newport City Council spokesperson
Newport City Council’s trading standards department is working with Newport company Welsh Bros. Foods Ltd following positive test results for horsemeat.
Investigations into the source of the contamination are ongoing and a product withdrawal is being overseen.
All action being taken is in line with Food Standards Agency guidelines.
Newport schools do not use this supplier; however, investigations into whether council care homes have purchased this specific product are being carried out.
Bridgend County Borough Council has confirmed it has stopped using frozen minced beef supplied by Newport company Welsh Bros Foods.
It comes after a sample of frozen mince from Welsh Bros Foods reportedly tested positive for horsemeat.
– Bridgend County Borough Council spokesperson
“While to date no health issues have been identified within Bridgend County Borough, we have stopped using frozen mince beef provided by one supplier as a precautionary measure.
This follows tests carried out by a neighbouring authority on a random sample of meat from the same supplier which tested positive for the presence of horse DNA.
We are liaising closely with our partners in the Wales Purchasing Consortium and the Food Standards Agency in this matter and will be carrying out further tests.
Pembrokeshire and Cardiff Councils have confirmed they have withdrawn certain beef products from use in schools and care homes following the announcement.
Welsh Bros Foods says it is 'deeply shocked' at the reported find but believes it is an 'isolated incident'.
Cardiff Council says it has withdrawn all Welsh Bros Foods beef products from its schools, leisure centres and care homes.
It follows news that a sample of frozen minced beef supplied by the Newport-based company has reportedly tested positive for horsemeat.
Pembrokeshire Council has also withdrawn mince from its menus following the announcement.
No products have yet tested positive for equine DNA in Cardiff, but the council says it has taken the step 'as a precaution'.
– Cllr Heather Joyce, Leader of Cardiff Council
I have no hesitation in taking this precautionary step whilst testing continues as it is vital that we do everything possible to identify whether there is any possibility of horsemeat DNA being in any of the products we use, and this process continues.
It is important that we move as quickly as possible to respond to the situation as it develops. I am pleased that so far we have not had any positive results for products we have tested for horse DNA but we have to continue to test and remain vigilant.
Welsh Bros Foods says it is 'deeply shocked' following the reported test result but believes it is an 'isolated incident'.
Welsh Bros Foods says it is 'deeply shocked' that a sample of its frozen minced beef has reportedly tested positive for horsemeat.
– Welsh Bros Foods spokesperson
Welsh Bros Foods regrets to announce that late yesterday afternoon we were informed that a formal sample of our frozen free flow minced beef has been reported to have potentially tested positive for above 1% horse meat. We have not as yet had formal confirmation on this result; however, we have taken the decision to notify our customers of this issue immediately, and issue a withdraw notice for this product.
Welsh Bros Foods are deeply shocked by this development and are working with all relevant authorities.
The firm said the affected batch was produced nearly three months ago and other samples have reportedly tested negative for horsemeat, adding: "We therefore believe at this stage that this is an isolated incident."