(Reuters) - Australian clothing retailer Cotton On Group is investigating its relationship with a Chinese printing firm suspected of using forced prison labor and which was recently suspended as a supplier by Tesco, ABC News reported.

The British supermarket giant suspended Zhejiang Yunguang Printing following a media report that a customer had found a message inside a Christmas card saying it had been packed by foreign prisoners who were victims of forced labor.

The ABC quoted a Cotton On statement as saying its “supplier code of conduct includes a zero-tolerance approach to any form of modern slavery, including forced labor.”

Cotton On did not immediately respond to a Reuters request for comment.

Tesco PLC said the Christmas cards were produced at the Zhejiang Yunguang Printing factory, about 100 km (60 miles) from Shanghai Qingpu prison. It said it was shocked by the allegations and is investigating the matter.

Zhejiang Yunguang did not respond to a request for comment, but China on Monday dismissed accusations of forced labor at the Shanghai prison.

The ABC reported that Zhejiang Yunguang Printing also lists Walt Disney Co and U.S. retailer Big Lots as international partners.

Big Lots and Disney did not immediately respond to a Reuters request for a comment.

Reporting by Shreya Mariam Job in Bengaluru; Editing by Edwina Gibbs