British Prince William's sister-in-law, Pippa Middleton, was photographed in a car in Paris as a male friend allegedly waved a gun at paparazzi, police said.

The Sun newspaper in London said Middleton was with three male companions in an Audi convertible when the driver took out the alleged weapon and pointed it at a French photographer following them.

The Paris Judicial Police are investigating the matter and it is possible Middleton could face charges if the gun turns out to be real, a source told The Sun.

“If the evidence points to her involvement, she will be prosecuted,” the insider said. “Anybody involved in the illegal use of a handgun in public is liable to arrest and interrogation.”

Prince William's mother, Diana, was killed in a 1997 car crash when her driver, who was intoxicated at the time, attempted to allude paparazzi following her in Paris. (UPI)