Sandwich chain Subway is the latest US fast food chain to become embroiled in a food-safety scandal in China.

A spokeswoman for the company says it is investigating Chinese media reports that workers at a Beijing restaurant used expired produce and “doctored” food labels.

Beijing’s food regulatory authority is also investigating the reports.

Similar media coverage led to a massive loss of sales after a supplier to the KFC chain was found using rancid meat and breaching other safety regulations earlier this year – although the Subway incident appears related to just one store. McDonald’s was also affected.

“Our headquarters here is now investigating the matter,” the Subway spokeswoman told a local news outlet.

“We want to investigate what caused the labeling issue and whether or not it was the action of a single franchised outlet,” she said.

No conclusions had yet been reached.

The news reports said the workers changed the production and expiry dates on meat, produce and juice packaging to allow older ingredients to be used past their expiration date and presumably reduce costs.

Subway has about 500 stores in China.