Alton Towers was forced to close a ride after a visitor reported an "object" falling from a rollercoaster.
The theme park launched an investigation after the incident on Saturday.
A source claimed to Stoke on Trent Live that the ride, Nemesis, had to be closed after a guest reported a falling object on their return to the station.
Alton Towers, however, said the person was not hurt, the incident did not compromise the ride's safety and Nemesis later reopened.
A spokesman said: "Nemesis was temporarily closed as a precautionary measure after a guest reported seeing a small falling object when returning to the station.
"Following extensive checks and a thorough investigation we now know that this was a small, non-structural washer that does not affect the ride's infrastructure.
"At no point was the safety of this ride compromised and the ride was re-opened for guests to enjoy.
"Health and safety is of paramount importance to the resort and we would like to reassure guests that comprehensive checks, similar to that of a car MOT, are conducted every morning and evening, as well as servicing of attractions throughout the year to ensure quality, safety and a first-class experience."
Alton Towers is the largest theme park in the UK, spanning 910 acres of land in central Staffordshire.
It is operated by Merlin Entertainments Group and incorporates a theme park, water park, spa, mini golf and hotel complex.
The theme park opened in 1980 and is home to over 40 rides and attractions.
It included the Corkscrew - Britain’s first double-loop rollercoaster - plus the Pirate Ship, Cine 2000 and the Wildlife Museum.