A top High Street fashion chain is investigating how two shoppers claim to have found labels sewn into summer dresses saying "sweatshops conditions" and "exhausting hours".
The two women have said they were shocked to see the hand-made labels sewn into bargain tops, which they claim were bought from the same Primark store in Swansea city centre.
Rebecca Gallagher, 25, spotted a label reading: "Forced to work exhausting hours" next to the washing instruction of her bargain top.
And a second shopper Rebecca Jones, 21, has revealed how she found another label reading: "Degrading sweatshop conditions".
The two women - who do not know each other - say they bought their £10 summer dresses from the same Primark store in Whitewalls, Swansea.
It comes after the discount fashion retailers have been criticised over working conditions of workers abroad - but Primark insists it has a strict code of ethics.
Mum-to-be Miss Jones said: "I was really shocked when I saw the label saying it was degrading sweatshop conditions.
"I used to shop a lot at Primark but not so much now. The label has made me think about how my clothes are made.
"I have no idea who made the label or how it go it there - but it does make you think."
Miss Jones, of Porthcawl, South Wales, said she tweeted a photograph of the label to Primark when she bought the blue dress from last year's summer range.
She said: "I tried to ring them as well but I was put on hold forever and then it just went dead.
"But then I heard about the other label from the same shop. I think Primark should get to the bottom of it."
Fellow shopper Miss Gallagher, 25, spotted the handmade label sewn into the multi-coloured top from discount store Primark.
She had vowed never to wear it again because of the fear it was made by a tired worker toiling in a foreign sweatshop.
Miss Gallagher, of Swansea, said: "I was amazed when I checked for the washing instructions and spotted this label.
"It was stitched by hand to say "Forced to work exhausting hours" and sewn in with the other normal labels.
"To be honest I've never really thought much about how the clothes are made.
"But this really made me think about how we get our cheap fashion.
"I dread to think that my summer top may be made by some exhausted person toiling away for hours in some sweatshop abroad."
The label reading "Forced to work exhausting hours" was stitched into the other labels giving Primark addresses in Spain and Ireland along with washing instructions.
Miss Gallagher said: "I've got no idea who put it there but it really took the wind out of my sails.
"It makes me think that it was a cry for help - to let us people in Britain know what is going on.
"I even rung Primark to ask them about it. But I was put on hold for 15 minutes before being cut off.
"I would dread to think that this might involve child labour and people's terrible working conditions.
"You hear all sorts of stories about people working in sweatshops abroad - it made me feel so guilty that I can never wear that dress again."
A Primark spokesperson described the label finds as "strange" and have asked the customers to give them the dresses for their investigation.
He said: "We are investigating the origins of an additional label which has been found in one of our dresses and whether there are issues which need to be looked into."
Primark's ethics came under fire in 2011 after the collapse of a garment factory in Bangladesh killed 1,000 workers, 580 of whom were employed by a Primark supplier.
The company recently announced it will pay out compensation to workers who were injured and the families of workers who died in the collapse.
The high street chain assured that it has "a code of conduct in place, to ensure products are made in good working conditions and all employees are treated fairly."
UPDATE: A woman from Northern Ireland has also come forward, with a 'cry for help' note, handwritten in Chinese, apparently found in a pair of Primark trousers.
Primark has voiced "growing suspicions" about the origin of the labels.