"We are foreign prisoners in Shanghai Qingpu prison China," the note read. "Forced to work against our will. Please help us and notify the human rights organization." The girl had accidentally uncovered the chilling connection between British Christmas festivities and how Chinese prisoners are working in factories to supply Western countries with holiday goods. 

Tesco said it was absolutely appalled on the reports of the Christmas card: "We abhor the use of prison labor and would never allow it in our supply chain," a Tesco spokesman said on Sunday.

"We were shocked by these allegations and immediately suspended the factory where these cards are produced and launched an investigation," the spokesman said.

The note also said: "Use the link to contact Mr. Peter Humphrey." 

Peter Humphrey is a former investigative journalist that spent several years in a Chinese prison that forced prisoners to work 15-hour days manufacturing clothing.