A report from an undercover investigation carried out by the Guardian and ITV News has alleged potential food safety breaches at a plant owned by UK-based supermarket chicken supplier 2 Sisters Food Group.

The supplier’s West Midlands plant, which is under investigation, produces fresh chicken for Tesco, Sainsbury’s, Marks & Spencer, Aldi and Lidl. All five retailers are reportedly investigating the allegations.

The Guardian and ITV News said it had evidence of workers tampering with the original slaughter dates of the poultry.

“We take any allegations of inaccurate labelling and breaches in hygiene regulations very seriously."

The report also said that during the investigation, some of the workers have confirmed practices related to inaccurate labelling, breaches in hygiene regulations, and non-compliance.

In response, 2 Sisters Food Group issued a statement that read as: “We view these allegations extremely seriously.”

“However, we have not been given the time or the detailed evidence to conduct any thorough investigations to establish the facts, which makes a fulsome response very difficult.

“However, we are never complacent and remain committed to continually improving our processes and procedures. If on presentation of further evidence, it comes to light any verifiable transgressions have been made at any of our sites, we will leave no stone unturned in investigating and remedying the situation immediately.”

Meanwhile, inspectors from the UK Food Standards Agency (FSA) found no evidence of breaches at the plant in question.

The agency has urged ITN and the Guardian to share any additional evidence, including witness statements, for this investigation.

FSA chairman Heather Hancock said: “We take any allegations of inaccurate labelling and breaches in hygiene regulations very seriously.

“Should we find any evidence of any risk to public health, any products on the market which we believe to be a cause of concern will be urgently removed from sale.”