Irish Government officials have denied they were aware that “thousands” of ex-racehorses, previously trained in Ireland, were being sent for slaughter to British abattoirs.

It emerged in an investigative programme that racehorses killed in British slaughter plants had been transported from Ireland, with some travelling more than 350 miles by road with critical injuries.

It is illegal under Irish and European law to transport a horse in a way that is likely to “cause it injury or undue suffering”.

In the BBC1 Panorama programme, aired on Monday night, it found that most of the 4,000 racehorses were Irish-trained.

Covert recording also appears to show serious breaches of regulations for slaughter plants.

A number of Irish government officials appeared before the Joint Committee on Agriculture, Food, and the Marine.

The agriculture department’s deputy chief veterinary officer Michael Sheahan said there were “a few issues” that came up in the programme.

“For me, probably, the most striking issue was around the whole area of horse slaughter,” Mr Sheahan told the committee.

“The footage from the abattoir in Swindon was probably the thing that struck home most with me.”

The footage captures dozens of horses apparently shot by a slaughterman who is standing yards away.

I'm happy to say that we're very satisfied with the way things operate in the slaughter plant here

Mr Sheahan told the committee that method of slaughter is not used in Ireland.

He said he has been involved in horse slaughter for 20 years, adding that the number of horses slaughtered in Ireland vary from year to year.

Ireland currently has two approved slaughter plants, with one closed following a fire at its premises.

He added: “I’m happy to say that we’re very satisfied with the way things operate in the slaughter plant here.

“They’re regulated in pretty much the same way as a beef slaughter plant or a sheep slaughter plant.

“We have a full time official Department of Agriculture vet present at all times when the slaughter is taking place.”

He added: “The single most surprising thing about the programme was the method of slaughter of the horses.”

Independent senator Ronan Mullen said what emerged from the programme was “extremely disturbing”.

“The picture we are getting in recent times in Ireland is that we might be a horse loving nation, and while there might be people in horse racing who do love horses, there’s seems to be a lot of people in the horse racing industry who don’t love horses,” he added.

“They see them as machines and entities to be used for making money.

“It is hard for us to believe you are very surprised at what went on in the documentary last night.

“I think most people will feel that you had a fair idea for some time that this kind of thing is going on.”

Dr Kevin Smyth, assistant secretary general at the department, said he had “no idea” what was happening.

“I categorically knew nothing about this until I saw what was on last night,” he added.

“I had no inkling whatsoever.”

We have an issue with traceability of horses in this country and it's spread across a number of regulatory bodies

Mr Sheahan also told the committee it was illegal to transport injured horses long distances.

“If it was the case that the animal was loaded on a box and transported 200 miles, that’s clearly illegal.

“I’m not sure that was the case.

“He could have been injured en route,” he added.

Mr Mullen was also critical of the traceability system in place for horses, accusing officials of failing to pursue an animal welfare agenda “with vigour”.

Mr Sheahan said there is a “need to move forward” with plans to update regulations this year.

Fianna Fail’s Joe Flaherty said it was “harrowing” footage.

“We have an issue with traceability of horses in this country and it’s spread across a number of regulatory bodies,” he added.

“We are a horse loving nation and we greatly pride and value our reputation as an equine nation but the onus has to come to the Department of Agriculture on the issue of horse ownership.”

He said that ownership and traceability of the movement of horses is a “grey area” in Ireland.

“We need to get horse ownership in Ireland, the traceability and where they are sold, how they are sold and where they are exported all into one central database,” Mr Flaherty added.

“In the modern age it’s inconceivable that we have not been able to hack that.”

Mr Sheahan said the traceability system in the horse sector is “nowhere near” as good as the cattle sector.

“We have a Rolls-Royce system when it comes to cattle,” Mr Sheahan added.

“In horses we don’t, but we have come a long way.”