Thieves allegedly used a stolen semi to take trailers full of engines, pulling off the heist in just six minutes.

Thieves have reportedly snagged around £3 million (~$3.8 million USD) worth of engines from Jaguar Land Rover's Solihull factory in the UK.

The brazen heist allegedly involved a stolen semi that pulled into the entrance gates on Tuesday, hooked up to a trailer full of engines and left -- all within six minutes, apparently with the necessary paperwork to show guards at a security checkpoint.

"Later that night the same lorry came back and did it all over again," a source told the Coventry Telegraphy. "It attached another wagon and then it drove out past the security guards and that wagon was not seen again all night."

The same source claimed approximately 40 engines can fit in a trailer, suggesting around 80 engines were presumably stolen from the factory. The particular type of engine is said to be used in Land Rover vehicles.

"The site is clearly not as secure as it should be," the source opined.