An investigation has found that 25% of abattoirs in England, Wales and Northern Ireland are failing to take basic hygiene precautions to stop contaminated meat reaching high street butchers and supermarkets.

Conducted by the Observer and the Bureau of Investigative Journalism, it found that there was major hygiene failings at more than 300 abattoirs.

Perhaps of more concern is that the investigation found that the failings could expose consumers to serious food poisoning illnesses such as E coli, salmonella or campylobacter.

One key test that abattoirs in the UK have to pass is that “all handling and processes from slaughtering to dispatch are done in a way that avoids the contamination of meat and offal entering the food chain”.

Out of the abattoirs audited, it found that 86 did not meet that benchmark – with “major” hygiene breaches found.

These breaches include instances of carcasses coming into contact with the factory floor, often dirty with the detritus of slaughter, cutting equipment not sterilised or washed adequately, and meat splashed with dirty water potentially containing faecal matter, according to the paper.

Furthermore, it found that official Food Standards Agency records were forged to hide the true levels of meat contamination at one English abattoir.

It was reported that a whistleblower said data relating to contamination of carcasses wasn’t recorded properly in order to hide poor hygiene practices at the plant. This could potentially allow dirty meat to enter the food chain.

Speaking to the paper, Professor Hugh Pennington, one of the UK’s leading microbiologists, said the FSA should make abattoirs take hygiene seriously.

If it was one in 100, even that would be too many, but one in four is unacceptable. This is basic hygiene. It’s not rocket science, it’s common sense.

“The FSA should be coming down on this like a ton of bricks. It’s very disappointing this is going on. The main risk is E coli O157, which my review looked into. The consequences can be catastrophic. People died.”