Participants can get £50 - but must permanently consent to the retailer using their personal data
Legal and consumer experts have expressed concerns about a cash giveaway by e-retailer, Temu.Participants in the promotion - which has gone viral on social media - receive up to £50, but have to agree to permanently hand over considerable amounts of personal data.
The data regulator says it is considering such concerns.
A number of other X users claimed the rules would allow Temu to sell their data or even create deepfake adverts - though those claims have been strenuously denied by the retailer.
She added that "While Temu isn't the first platform to excessively hoover up data, there are definite question marks over whether requesting permission for personal data to be used 'worldwide' is proportionate in any circumstances."
Jonathan Kirsop, data protection partner at law firm Pinsent Mason, told BBC News it was not a wording he had seen used commonly before and the activity implied may be "Problematic".
"While not always prohibited, making the provision of services conditional on a consent to the use of personal data will often be unlawful on the basis the user may not be considered to have a free choice in delivering that consent, particularly where the data concerned is sensitive, such as biometric data," he said.
The use of voice data - which is considered biometric data under the UK's General Data Protection Regulation - has a higher threshold for lawful use and consent in the UK because it carries greater risks, he added.
The data regulator, the Information Commissioner's Office, said it was "Aware of reports about Temu" and was "Considering the concerns raised."
In a statement it added: "Organisations must be clear and transparent about how and why they collect and use people's personal information, and ensure people can make a fully informed decision as to whether to hand over their data."
"Whenever there is such a deal being offered we must always look at: what is the consequence of this, and how much of our data is going to be collected, how it is going to be used, and are we comfortable with that?" he said.