Mystery sinkhole swallows classic Corvettes at US museum

The damage caused by a sinkhole, which swallowed up eight rare cars, at the National Corvette Museum in Kentucky. (National Corvette Museum)

A giant mystery sinkhole has swallowed eight rare cars at a sports car museum in the United States.

The sinkhole, reported to be 40ft wide and at least 20ft deep, opened up at the National Corvette Museum in Bowling Green, Kentucky, in the early hours of Wednesday morning.

According to CNN, motion detectors had alerted security that something was amiss shortly after 5.30am. The museum claim that the damage caused by the hole - in addition to the eight cars lost in the incident - could cost in excess of "millions of dollars".

An employee who first walked into the room "has been in shock all day," said the museum's spokeswoman Kate Frassinelli.

"When you go in there, it's unreal," she added. "The hole is so big, it makes the Corvettes look like little Matchbox cars."

Among the cars lost in the damage were a 1962 Black Corvette model, along with the 1992 "One Millionth" Corvette and six others.

Six of the cars were donated by the sports car makers' enthusiasts, with two on loan from General Motors, with executive director Wendell Strode claiming the value of the cars damaged is "substantial".

It serves as a blow to the museum, which was preparing to celebrate its 20th anniversary with the unveiling of a 184-acre motorsports park in August.