19 November 2013 Last updated at 21:04 ET
Traffic and footsteps caused an ancient Egyptian statue to rotate inside its glass case, an investigation has found.
Curators at Manchester Museum were left baffled when a time lapse video caught the 10ins (25cm) high stone statue, which dates back to 1,800 BC, moving.
Vibrations expert Steve Gosling placed a specialist three-axis sensor under Neb-Senu's glass cabinet to record its movement over 24 hours.
He said the convex base of the figure made it "more susceptible" to rotate.
The sensor revealed traffic and footfall vibrations at busy times of the day, such as 18:00 GMT and 07:00 GMT, caused the statue to rotate.
Mr Gosling, of 24 Acoustics engineering noise consultancy, said: "The vibration is a combination of multiple sources so there's buses outside on the busy road, there's footfall activity."
Movement ceased overnight.
"There's a lump at the bottom which makes it more susceptible to vibrations than the others which have a flat base," Mr Gosling added
Before the test, Egyptology curator Annie Garnett said various theories had been advanced ranging from vibration caused by nearby traffic to visitor footfall.
The statue was donated to the museum by a private collector in 1933.
Testing was undertaken for ITV's Mystery Map series which investigates myths and mysterious stories.