One video revealed a Shein clothing tag that read: "Tumble dry, do not dry clean. Due to the water-saving technology, need your help washing with the soft detergent at the first time to make the goods softer."
Another video shows a slip of paper that reads "help me plz" and a mailing label with "HELP ME" printed on it.
There's also footage of a handwritten note in Chinese characters, with "SOS! SOS! SOS!" at the top.
One Twitter user has asked for a serious investigation into Shein's practices after the allegations surfaced on TikTok.
Another wrote, "This is a bit creepy".
People have started to ditch the hauls, instead posting video messages to boycott the brand and discourage buying fast fashion.
Leading fashion-rating site Good On You gave Shein its lowest grade - "We avoid" - labelling its sustainability practices "very poor".
Meanwhile, Shein is denying the TikTok allegations, calling them a "conspiracy".
"Recently, there has been some confusion about one of our product labels," the company said.
"Our intention was to remind customers to help soften this fabric by using a softener when washing the garment for the first time. The fabric is digitally printed, a process which reduces the use of water, as opposed to traditional, water-intensive textile printing."
"We also want to make it clear that we have a strict code of conduct for suppliers, which forbids them to use forced labour."
But many are still questioning the company's practices.
One TikToker asked, "So wouldn't it be on all your labels?"
Another asked, "Can we see how the workers work?"
Business Insider has reported that Shein's business model relies heavily on overconsumption, with customers rewarded with extra perks based on how much they spend.
On its website, Shein claims all its workers are paid "living wages" and says it "strictly" abides by laws prohibiting child labour.
