Issues found during inspection at Scotland site same day production was suspended at Midlands plant, it was revealed this week

Dave Lewis, the chief executive of Tesco, has “some explaining to do” about why the company did not reveal its inspectors had unearthed “major” process issues at a second 2 Sisters Food Group factory, an influential MP has said.

The supermarket chain conducted a series of emergency inspections of 2 Sisters poultry factories as a direct response to a Guardian and ITV undercover investigation into its West Bromwich site at the end of September.

It was revealed this week that 2 Sisters’ Coupar Angus site in Scotland received what Tesco described as a “red” warning rating because of process issues identified during one of those inspections, on the same day as production was being suspended at the chicken processor’s West Bromwich plant.

In parliament on Thursday, John Grogan , a Labour member of the environment food and rural affairs committee, said: “I think Mr Lewis has some explaining to do. Why did Tesco not provide this information, not just to the public but to the Food Standards Agency? All supermarkets should definitely do this in the future.”

Tesco said it “works closely” with the regulator and had shared “the key findings from our inspections at 2 Sisters Food Group with the FSA”. The supermarket chain handed the full Coupar Angus report to the FSA after being contacted by the Guardian and ITV.

Three days after production at the West Bromwich site had been temporarily suspended and Tesco inspectors had filed their Coupar Angus report, Lewis was asked at a press conference about what failings had been found internally by 2 Sisters that were serious enough to halt West Bromwich’s production.

He declined to answer, but said the supermarket had since inspected all 12 of 2 Sisters’ chicken factories and that he believed the problems were contained to the one site.

Lewis said: “Having been to all the other [sites] … we didn’t find anything that would indicate that what was seen in West Bromwich was present in any of the other factory sites. We did go to all other factories, so we don’t think our inspectors have had the wool pulled over their eyes.”

Tesco said Lewis was talking about his inspection teams finding no evidence of food safety risks at 2 Sisters sites and that the chief executive was not routinely told about red ratings unless food safety breaches are identified.

The process problems unearthed at Coupar Angus were all distinct from the issues in West Bromwich, where chicken was filmed being returned to the production line from the floor. Tesco insisted the Coupar Angus process issues “were addressed immediately to prevent any food safety issues”.

The 2 Sisters Food Group has denied the West Bromwich undercover footage showed any food safety breaches and said it temporarily suspended production in West Bromwich because of “isolated instances of non-compliance with our own quality management systems”.

Tesco’s Coupar Angus inspection did not find consumers had been put at risk or breaches of food safety.

A spokesman for 2 Sisters said: “ITV and the Guardian are referring to standard inspection audits and appear to be trying to damage the reputation of our factories and potentially the livelihoods of 23,000 colleagues by misrepresenting them. There is and never was any risk to food safety at Coupar Angus. This is using old news to highlight issues which were resolved with our customer two months ago.”