A shopper got a bit of a shock when she bought a floral dress from a branch of Primark (which trades in Ireland as Penneys) in Swansea, Wales.

When Rebecca Gallagher checked inside the €12 dress, she found a hand-stitched label bearing the words: “Forced to work exhausting hours.”

"I was amazed when I checked for the washing instructions and spotted this label," Gallagher told the South Wales Evening Post.

"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,” she said.

“I dread to think that my summer top may be made by some exhausted person toiling away for hours in some sweatshop abroad.”

While it is unclear where the label was made, a spokesman from Primark said there had been "no other incidents of this kind".

"We would be grateful if the customer would give us the dress, so we can investigate how the additional label became attached and whether there are issues which need to be looked into," he said.

Primark has come under scrutiny before for the treatment of its suppliers' workers. In March, the high street chain began paying out more than $9m in compensation to victims of the Rana Plaza factory collapse in Bangladesh. One of Primark's suppliers was based in the building that collapsed in April 2013, killing more than 1,100 people.

Rebecca said that she believes the label came from someone reaching out for help.

"It makes me think that it was a cry for help — to let us people in Britain know what is going on.”

[H/T: Vogue]