China factory

Tesco halts production at Chinese factory over alleged 'forced' labour

The note, found by Florence Widdicombe, was allegedly written by prisoners in Shanghai claiming they were "forced to work against our will".

"Please help us and notify human rights organisation," the message said.

Tesco said it was "shocked" by the report, adding: "We would never allow prison labour in our supply chain."

The supermarket said it would de-list the supplier of the cards, Zheijiang Yunguang Printing, if it was found to have used prison labour.