Online marketplace Amazon has told customers who bought certain "hoverboards" to throw them out after concerns they can catch fire.
In an email, the firm told buyers of self-balancing scooters with "non-compliant UK plugs" to dispose of the product at a recycling centre.
Such customers would be automatically refunded within three days, it said.
It comes after Trading Standards seized 15,000 unsafe boards being brought into the UK.
Many had faulty cables, chargers or plugs that could catch fire or explode, it said.
Amazon is understood to have stopped selling the devices. Retailers Argos, John Lewis have also reportedly pulled them from sale.
A Tesco spokesman said: "We've suspended the sale of all hoverboards both in store and online as a precautionary measure."
In the email, Amazon said: "We regret the inconvenience this may cause you but trust you will understand that your safety and satisfaction is our highest priority."
It advised customers to dispose of their product at a centre registered to recycle electrical items "as soon as possible", and said a refund was being automatically processed.
Such customers could contact Amazon customer services if they did not wish to keep the product, the firm said.
Earlier this month, Trading Standards officers said they had seized 88% of all scooters examined since October 15, mainly for having non-compliant electrical components that could explode or catch fire.
Many of the boards were found to have plugs without fuses, and cut-off switches which failed when tested.
Chargers, cabling and batteries were also found to fail safety standards.
The London Fire Brigade has warned that at least three house fires were caused by such devices over 10 days in October.
Advice to consumers
Trading Standards is giving these tips to consumers who have bought a "hoverboard", or are thinking of buying one:
- Never leave the device charging unattended, especially overnight. A faulty cut-off switch means it could overheat
- Check the plug. Many faulty devices have a "clover-shaped" plug
- If buying online, be careful to check the website is genuine and has a contactable phone number and address
- Don't be dazzled by prices which seem too low
Anyone who finds such products for sale is being urged to contact the Citizens Advice helpline on 03454 04 05 06.
The Retail Ombudsman watchdog urged UK retailers to remove unsafe devices from sale or "face the risk of the full force of the Consumer Protection Act".
Chief ombudsman Dean Dunham said retailers could be held liable for any injuries caused by unsafe goods.
He told BBC Radio 5 live that people who have bought any type of hoverboard should return them to the place they were purchased from to obtain a refund.
"I think you've got to err on the side of caution and take it back. We don't know enough information about these to be able to go out to the public and say, 'If you spend a lot of money on one of these, it will be fine'."
What is a hoverboard?
- "Self-balancing scooters" are known by various names including "hoverboards" and "rideables"
- Gyroscopes are used to counter-balance and control the speed of the wheels - with some models capable of travelling at up to 12 mph
- They are banned from use on public pavements and roads in the UK
- The Crown Prosecution Service has issued guidance stating they "are not legal for road use"
- According to the Department for Transport, it is only legal to use them on private property with the owner's consent
- The same applies to Segway scooters, with one Yorkshire man successfully prosecuted and fined £75 for riding one on the pavement
A number of airlines, including leading airline groups American, Delta and United, have banned passengers from taking so-called hoverboards onto flights, saying their batteries present an unacceptable fire hazard.