Motley Crue star Tommy Lee has been hit with a lawsuit by an engineer who claims the rocker stole his idea for a drum kit rollercoaster.
Lee uses drum kit stunts during the band's shows and on their 2011 tour; he was seen turning upside down as he played.
Los Angeles-based engineer Scott King sent a legal letter to the band's attorneys last month, alleging he pitched a similar concept to Lee in 1991 but the idea was dismissed.
He claims Lee stole his idea and threatened to take legal action over the dispute - and now he has followed through on his promise.
King filed papers in L.A. County Superior Court and is demanding at least $400,000 in damages, according to TMZ.com.
Lee's representatives have yet to respond to the lawsuit, but at the time of King's legal threat, the star's lawyers reportedly fired a letter back to him, insisting the rocker never received a pitch and that the two ideas were totally different.