Species star Natasha Henstridge has been caught in a steamy sexual encounter with British former Pop Idol star Darius Danesh.

The romantic couple were spotted lunching in Hollywood hotspot Toast, before enjoying a moment of passion in the 31-year-old actress' car.

After lunch the pair drove off in Henstridge's Range Rover and made their way to the nearby Fairfax District neighbourhood. Henstridge pulled the car over in front of a house and two began getting hot and heavy.

An eyewitness says, "I couldn't see their heads and then I drove by and saw his seat reclined back and she was over on his side of the car. Her head would pop up occasionally to make sure no one was around.

"They were parked there for at least 20 minutes. The neighbours came home and she jumped back to her side of the car. It looked like she was trying to put her pants back on."

Danesh, 25, is in Los Angeles working on his third album and Hestridge most recently appeared in the Geena Davis drama Commander-in-Chief.