More than 30 people were stuck on the Smiler rollercoaster at Alton Towers after debris reportedly fell from a carriage.
The ride had to be closed after it stopped at midday yesterday.
The Merlin Entertainments-owned theme park said all visitors were evacuated from the ride in 30 minutes.
The incident at the Staffordshire attraction came 14 months after five people were seriously hurt in a crash on the Smiler ride.
A statement from the theme park said : “Alton Towers Resort stopped the Smiler to investigate claims a piece of debris had fallen from a carriage.
“At no time were guests on the ride at any risk and all were safely removed promptly by staff in line with our standard procedures.”
The ride was re-opened at 4.22pm after The Smiler was declared safe after an inspection by the park’s technical team.