Safety regulators in the US have urged owners of a Peloton treadmill to stop using the product "immediately" if they have children or pets in the home.
The Consumer Product Safety Commission (CPSC) says it is aware of 39 incidents including one death, involving the Peloton Tread+.
Peloton had already confirmed the death last month and said children should stay away from the machines.
On Saturday, Peloton called the CPSC's warning "inaccurate and misleading".
Peloton sells cycling machines and treadmills that can be connected online to virtual fitness classes. Its business has boomed as people look for alternative ways to exercise during lockdowns and gym closures.
The CPSC issued the "urgent warning" on Saturday, releasing video footage of a child being dragged under one of the machines.
It said the machine posed "serious risks to children for abrasions, fractures, and death".
Stop Using the Peloton Tread+ pic.twitter.com/afRBom78qo— US Consumer Product Safety Commission (@USCPSC) April 17, 2021
The CPSC said it believed at least one of the 39 incidents occurred while a parent was running on the treadmill. It also warned that children could be seriously injured while the Tread+ is being used by an adult and not just during cases where children have been left unsupervised.
The regulator advised owners of the machine to use it only in a locked room and to keep objects such as exercise balls away from it.
Peloton said in a press release that the machine was "safe for members to use in their homes and comes with safety instructions and warnings to ensure its safe use".
"Like all motorised exercise equipment, the Tread+ can pose hazards if the warnings and safety instructions are not followed," it added.
The company told owners of the machine not to let children under the age of 16 use the treadmill and to keep children, pets, and objects away from the Tread+ at all times.