Supermarkets are removing tins of Brazilian corned beef from their shelves following allegations that the products could contain meat linked to slave labour on cattle farms.
Waitrose is taking its own-brand corned beef from Brazil off its shelves and Lidl and The Co-op have also launched inquiries as a result of an investigation by the Guardian and Brazilian journalists.
The newspaper said documents obtained by it and Reporter Brasil showed that meat processing company JBS previously bought cattle from a farm under federal investigation for using workers as modern-day slaves.
JBS told the Guardian it stopped buying from the farm on discovering the alleged link to labour abuses.
The company exports meat products to 150 countries around the world and its tinned corned beef has been sold by UK retailers including Waitrose, Marks & Spencer, The Co-op, Sainsbury's and Lidl.
The Guardian said it had seen official documents showing JBS paid £2 million between 2013 and 2016 for cattle reared on a farm in the northern state of Para, where prosecutors claim workers were being subjected to modern slavery as defined under Brazilian law.
In a statement to the newspaper, JBS said the farm was not included in the government's official "blacklist" of companies known to use slave labour, adding that it had ceased buying from the farm.
JBS said in the statement: "As soon as JBS became aware of irregularities in the ... farm's operations in 2016, all livestock purchases from the Junqueira family were immediately stopped.
"JBS does not buy cattle from any farms which have any association with slave labour, as listed by the Brazilian government and updates all of the information contained in ... the ministry of labour 'black list' of slave labour on a daily basis."
Waitrose said: "While we have found no such concerns in our own supply chain (and have recent audits, including April 2017), we are taking these allegations seriously so have stopped sourcing any of our corned beef from there while we investigate fully."
A spokesman for the Co-op said: "Co-op has pioneered ethical trading for more than 170 years and tackling modern slavery is a core part of our ethical trade strategy.
"We have a sourcing code of conduct in place and audit suppliers against international labour standards, to ensure all workers in our supply chain are treated fairly and to ensure high standards are upheld.
"We take such allegations very seriously and will be investigating with our suppliers in order to address any issues."
Lidl said: "Whilst Lidl UK does not source directly from JBS, we are working closely with our supplier to address the allegations.
"Several years ago, Lidl defined its social and environmental expectations from its business partners in its Code of Conduct.
"In it, Lidl rejects any form of exploitative labour or the abuse of human rights and labour laws across our supply chain."
An M&S spokesman said: "We have not sourced canned corned beef from Brazil since Autumn 2016. All of our canned corned beef is now made from British beef."