Tesco suspended productions of a greeting card at a factory in China after a 6-year-old girl in England found a letter about forced labor from prisoners in Shanghai.

Florence Widdicombe, the 6-year-old girl, opened a box of charity Christmas cards from Tesco so she can send them to her friends.

Along with the cards, Florence found a hand-written note.

The message said, “We are foreign prisoners in Shanghai Qingpu prison China.”

It added, “Forced to work against our will. Please help us and notify the human rights organization.”

The letter then asked the reader to contact Peter Humphrey, a former journalist, who was once in Qingpu Prison.

Since the discovery, Tesco halted production at the factory.

Tesco stopped the production of particular cards and said that they were shocked by the investigation.

Tesco will de-list Zheijiang Yunguang Printing, the supplier of the cards if they are guilty of using prison labor.

Tesco said, “We would never allow prison labor in our supply chain.”

Florence, the kid, said the incident made her feel shocked.

Florence said she is going to write her cards from now on.

The family explained what happened to Florence, and the kid said she felt sad.

Ben, the father of the 6-year-old girl, initially thought that the note his daughter found in the car was a prank.

Ben later realized that the note was something serious.

Ben said, “I felt very shocked but also felt a responsibility to pass it on to Peter Humphrey as the author asked me to do.”

Peter Humphrey, a former journalist, wrote up the story.

In the story that he wrote for the Financial Time, Humphrey said, “It hits home. There are injustices in the world and there are people in difficult situations and we know about that and we read about that each and every day.”

It added, “There is something about that message hitting home at Christmas… that really does make it very poignant and very powerful.”

It continued, “It could have ended up anywhere. And indeed we have many cards as all families do that are left over and we put them in a drawer and forget about them. There is an incredible element of chance in all of this that the card was written, it got to us and we opened it on the day we did.”

Humphrey was released from prison in June 2015.

At the time of his release, Humphrey said that Qingpu made product tags with the names of high street brands.

Tesco released a statement about the incident.

A spokesman for Tesco said: “We abhor the use of prison labour and would never allow it in our supply chain. We were shocked by these allegations and immediately suspended the factory where these cards are produced and launched an investigation. We have also withdrawn these cards from sale while we investigate.

The spokesman added, “We have a comprehensive auditing system in place and this supplier was independently audited as recently as last month and no evidence was found to suggest they had broken our rule banning the use of prison labour. If a supplier breaches these rules, we will immediately and permanently de-list them.”