Horse meat is popular on the continent

During research, reporters saw large numbers of ponies ending up in the abattoir after being sold for �1.

At one market in Llanybydder, west Wales, the programme makers claim that, after being sold during the day, one group of horses were left without food and water all night.

Both the auctioneers and the haulage company in questions strongly deny the claims.

The RSPCA's Elin Davies said: "We will be looking at evidence we have been given and considering what to do."

Overbreeding

Demand for horse meat to be exported from Wales to the continent has risen as a result of the BSE outbreak as it is considered safer than beef in some parts of Europe.

Some breeders are now calling for stricter rules to prevent overbreeding, which has led to the drop in price.

Ann Roberts, horse expert

Horse expert Ann Roberts said: "There seems to be a trend towards farming ponies, particularly the smaller breeds, the Shetlands, smaller Welsh breeds, the New Forest ponies.

"Possibly we should be looking at some sort of quota," she added.

Last year, a separate investigation carried out by the charity Compassion in World Farming (CIWF) also claimed that ponies were being "cruelly and illegally treated" at markets.

A European Commission report then called for harmonised rules on the transportation of live horses and ponies between European countries.

Taro Naw is broadcast at 2100 BST on S4C on Monday