An investigation by the BBC has found evidence of a criminal conspiracy to move horses, not fit for human consumption, to the UK from Ireland and into the food chain.

The investigation, revealed today (6 March), claims horses were moved via a smuggling route that in the majority of cases started in Ireland. The BBC revealed the horses were given fake documentation and drugs to make them appear healthier before being delivered to an abattoir in Cheshire.

One of those involved in the conspiracy told the BBC anonymously: “People knew. They knew they were going to a factory but people thought they were going for dog food.”

He was part of a gang which transported animals unsuitable for the food chain on forged papers.

The horses were fitted with “bogus micro-chips” and given drugs to make them appear healthier, the BBC said.

“The practice is said to have been going on for years. It is not known where the horsemeat ended up,” the news service noted.

The Cheshire-based abattoir told the BBC it had “never knowingly slaughtered any horse with false documentation” and claims it turned away many from Ireland mainly due to inadequate passports.

The authorities in Northern Ireland, however, accept that checks need to be tightened.

Chief veterinary officer for Northern Ireland Bert Houston told the BBC: “We are looking at all of the ways in which we might harden the resistance of the system to the abuse.”