Published Wednesday, 25 June 2014
A shopper from Co Fermanagh contacted Amnesty International when she discovered the handwritten note earlier this week.
The message is headed "SOS! SOS! SOS!" and has since been translated from its original form.
According to Amnesty, it reads: "We are prisoners in the Xiang Nan Prison of the Hubei Province in China. Our job inside the prison is to produce fashion clothes for export.
"We work 15 hours per day and the food we eat wouldn't even be given to dogs or pigs. We work as hard as oxen in the field.
"We call on the international community to condemn the Chinese government for the violation of our human rights!"
The trousers were purchased by Karen Wisínska in June 2011, but had remained unworn and in a cupboard until now.
I am only sorry that I did not discover the note when I first purchased the clothing - then I could have brought this scandal to light much earlier.
Karen Wisínska, shopper
Ms Wisínska told Amnesty that she had been shocked by the discovery and even more shocked by the translation of the message.
Patrick Corrigan, Northern Ireland Programme Director of Amnesty International, said it was a "horrific" story.
"It's very difficult to know whether it's genuine, but the fear has to be that this is just the tip of the iceberg," he said.
"There is no excuse for any UK company to be profiting from forced labour in Chinese prisons. They should be monitoring their supply chains and terminating contracts when they discover abuses.
"The Government should now amend its Modern Day Slavery Bill to require companies to keep their supply chains free of such abuses."
On Monday, Primark launched an investigation after a similar situation was brought to light following a purchase of a dress at a store in Wales.
A message was stitched into label alleging "sweatshop conditions" had been used to make the item.
In a statement, the company said it takes the allegations "very seriously".
While concerns have previously been raised about the conditions for those making the low-cost garments for the store, Primark's Code of Code - as outlined on its website - states "good working conditions" must be in place and that workers must be "treated decently and paid a fair wage".
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