Updated

It sounds like the opening scene from a spy novel.

Mercedes-Benz 300SLR

Two Mercedes-Benz 300 SLR Uhlenhaut Coupes were built, but never raced or sold. (Mercedes-Benz)

A handful of the world's richest car collectors secretly gathered in a closed museum to bid on an ultra-rare historic car.

That's reportedly what happened on May 6 at the Mercedes-Benz museum in Stuttgart, Germany, when someone paid $142 million for one of the cars in the collection.

Mercedes 300 SLR

The Mercedes-Benz 300 SLR Uhlenhaut Coupe was based on the 300SLR roadster. (Uhlenhaut's)

Sources familiar with the event told classic car lifestyle and insurance company Hagerty that it was the second of two 300 SLR "Uhlenhaut" coupes Mercedes-Benz built for the 1956 racing season. Hagerty was able to confirm that the museum was closed to the public for a private event on the day in question.

Mercedes-Benz 300 SLR

The Mercedes-Benz 300 SLR Uhlenhaut Coupe was intended for racing before Mercedes-Benz discontinued its Motorsports activities. (Michael Cole/Corbis via Getty Images)

The cars are hardtop versions of the 300 SLR roadster that was involved in the tragic crash at the 1955 running of the 24 Hours of Le Mans that killed 84 spectators and led to the discontinuation of Mercedes-Benz's official racing activity for 30 years.

As such, the coupes were never raced during the era or previously sold, but they have appeared on track at more recent historic events. Their nickname name comes from the head of the testing department that developed them, Rudolf Uhlenhaut.

A Mercedes-Spokesman told Fox News Autos that the automaker often receives requests to buy vehicles from its collection, but would not confirm this event or the sale happened.

"The market for classic cars is constantly in motion and so there is always a lot of speculation. Please understand we are unable to participate in such speculation," he said.

Mercedes-Benz 300 SLR

the Mercedes-Benz 300SLR Uhlenhaut Coupe has made appearances at historic racing events. (Michael Cole/Corbis via Getty Images)

According to Hagerty, the potential buyers were chosen both for their means and willingness to maintain the vehicle with the same care Mercedes-Benz has.

If the story is accurate, the sale would be a new all-time record price paid for a car, eclipsing both the $70 million that WeatherTech founder David MacNeil reportedly paid in a private sale for a 1963 Ferrari 250 GTO in 2018 and the $48.4 million that a 1962 Ferrari 250 GTO went for at an RM Sotheby's auction the same year.