A Chinese printing company accused of using prison labour to make Christmas cards sold at Tesco supermarkets in the United Kingdom is also a supplier to Australia's Cotton On Group — a relationship the group is now investigating.

Key points: Cotton On lists Zhejiang Yunguang Printing as a supplier on its website

Cotton On lists Zhejiang Yunguang Printing as a supplier on its website It has been alleged that the Chinese company uses forced prison labour

It has been alleged that the Chinese company uses forced prison labour Tesco has suspended its relationship with the company pending an investigation

The forced labour allegations emerged after a six-year-old girl in London discovered an apparent plea for help written inside a Christmas card, which was made by the company Zhejiang Yunguang Printing and sold at the supermarket chain Tesco.

"We are foreign prisoners in Shanghai Qingpu Prison China. Forced to work against our will. Please help us and notify human rights organisation," the note in the Christmas card said.

There are many foreign citizens detained at the Qingpu prison: former inmates include the British journalist Peter Humphrey — who the author of the note made a direct reference to — and Australian Stern Hu, a former Rio Tinto executive.

The author of the note asked whoever found it to contact human rights organisations. ( Reuters )

Tesco immediately suspended its relationship with Zhejiang Yunguang Printing and withdrew the Christmas cards from sale, pending the outcome of an investigation into the forced labour allegations.

"We abhor the use of prison labour and would never allow it in our supply chain," a Tesco spokesman said.

However, Zhejiang Yunguang Printing also manufactures products for the Cotton On Group, which owns a variety of retail brands across Australia, including Cotton On, Typo and Supre.

The Chinese company was named in Cotton On's most recent official supplier list, and Zhejiang Yunguang Printing also claimed to make products for the Australian brand in a corporate video on its website.

Cotton On was listed as one of the Chinese company's top international partners, alongside Tesco. ( Zhejiang Yunguang Printing )

In the video, Zhejiang Yunguang Printing listed Cotton On as one of its top international partners, alongside Tesco, Disney, and the US retailer Big Lots.

There is no suggestion that the products Zhejiang Yunguang Printing supplies to Cotton On are made through forced labour.

In a statement to the ABC, Cotton On Group said it had launched an investigation in to the supplier.

"Our Ethical Sourcing Program [established in 2009] is underpinned by our 14 Rules to Trade," Cotton On's corporate affairs manager, Antoinette Marshall, told the ABC.

"This supplier code of conduct includes a zero-tolerance approach to any form of modern slavery, including forced labour."

The ABC has also approached Disney and Big Lots for comment, but they did not respond by the time of publishing.

It is not the first time this year that the Geelong-based Cotton On Group's supply chain has come under scrutiny.

Cotton On stopped sourcing cotton from China's Xinjiang region in October, amid concerns about human rights abuses against Uyghurs and other mostly Muslim minorities there.

More than a million people across Xinjiang have been detained in re-education camps, which China refers to as "vocational training" centres.

The company's decision came after Four Corners revealed a Cotton On staff member had visited the factory of Xinjiang-based supplier, Litai Textiles, located just 6 kilometres away from a massive re-education camp.

Cotton On said at the time it was "absolutely committed to having an ethical supply chain".