Gardai were last night investigating the circumstances which led to the massive pig meat scare at the weekend.

Senior officers from the Republic’s National Bureau of Criminal Investigations met Department of Agriculture officials to try to establish the source of the scare.

They will try to identify where all elements of the feedstuff at the centre of the recall came from.

Last night, the cost of the pork scare was forecast to hit €1bn as the recall of affected products went global and hundreds of thousands of consumers were forced to dump pig-meat products.

It emerged that contaminated product had gone to as many as 30 countries worldwide, leaving Ireland’s reputation for quality agricultural produce in tatters. And as supermarkets were forced to remove millions of euro of pork from their shelves, there were serious doubts about consumers’ prospects of getting their money back.

Last night only three supermarket chains were offering full refunds, with just two saying they would recompense those who didn’t have receipts for pork products, which have been linked to cancerous PCB dioxins.

Millstream Recycle, based in Bunclody, Co Wexford, emerged as the company at the centre of the food scare and was shut down as further tests took place.

The Food Safety Authority Ireland said that industrial oil had tainted ingredient at the company, which uses recycled bread and dough in production.

Officials are now probing links with an oil used in a machine at the food processor plant, which was closed down in the middle of last week when the contaminated feed was traced.

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 €750m.

The latest scare amounts to a major new hammer blow to the Irish economy at a time when it needs every euro of income. Between 20 and 30 countries may have received contaminated shipments according to Irish officials — including the UK, France, the Netherlands and Belgium.

Taoiseach Brian Cowen last night insisted that pork products would be back on display as quickly as possible in a bid to boost consumer confidence.

The pork recall has sent shockwaves through the agricultural industry, and particularly the embattled pig production and processing sector. Not since the foot and mouth outbreak of 2001 has such drastic action been taken by the Republic’s authorities.