Police say they are "taking into account" a fatal accident at a theme park in the US a few weeks after a teenager's death at Oakwood in Pembrokeshire.
The Hydro ride has been closed until further notice at Oakwood
Hayley Williams, 16, from Pontypool, died after falling 100ft from the Hydro ride at the park in April.
This week it emerged that the same company who made the safety restraint for the Hydro ride was also responsible for the system on the American rollercoaster.
The Superman Ride Of Steel at the Six Flags theme park in New England was closed for a month after Stanley J Mordarsky was killed in May.
The 55-year-old, from Connecticut, who had cerebral palsy, came loose from a lap restraint on the rollercoaster and plunged to the ground.
The rollercoaster claims to be one of the tallest and fastest in the world, with a height of up to 208ft and a speed of up to 77mph
Hayley Williams was airlifted to hospital but died from her injuries.
A report by the Department of Public Safety in Boston recommended modifications were made to the safety restraint on the ride and it reopened earlier this month.
A spokeswoman for the department told BBC Radio Wales that the man had not been secured properly.
She said their main concern lay in the feasibility that there could be a problem in securing people who were a particular shape - if they were either too thin or too wide.
The safety restraint was made by Swiss company Intamin AG, who also made the safety system for the Hydro ride at Oakwood.
In the meantime in California, state officials with the Department of Occupational Safety and Health earlier this month asked two theme parks to close rides until modifications on similar restraint systems were made.
Three years ago, restraining straps on a theme park ride made by Intamin were modified after a fatal accident at a theme park near Los Angeles.
State authorities there found that restraints may have been inadequate although the woman's weight was also a factor.
Dyfed-Powys Police and the Health and Safety Executive are still both holding investigations into the Oakwood accident and the ride remains closed.
A police spokesman said they will take into account incidents in other countries, but the investigation here is a separate inquiry and it will have its own conclusions.
Almost 100 witnesses have been interviewed so far and police say they expect the investigation to take several more months to complete.
A spokesman for Inatmin told BBC Radio Wales that it would not be making any comment as the investigation was on-going.
An inquest has been opened and adjourned into Hayley's death.