Pippa Middleton was questioned by cops in Paris on Sunday night, after her friend was seen brandishing a pistol as he drove her in his Audi convertible.
He waved the gun in the air and pointed it at a photographer, whose snaps show the chilling moment when the gun (which looks like a semi-automatic) stared straight down his lens, the Sun reported.
Pippa, 27, can be clearly seen in the front passenger seat.
Last night, the Paris Judicial Police were poised to launch a probe as a source divulged that Pippa would face arrest amid a gun clampdown.
"If the evidence points to her involvement, she will be prosecuted. Anybody involved in the illegal use of a handgun in public is liable to arrest and interrogation," the source said.
The source affirmed that if the gun was real, brandishing it in a public place is punishable by up to seven years’ jail "for all parties involved."
And even if it was fake, the maximum jail term is two years.
"Certainly if you were in a car and knew somebody was using a gun to warn people off you’d be liable to arrest."
The French photographer was even "considering his options" over making a formal police complaint.
"Waving a weapon in public is not only illegal — it’s incredibly stupid," a security source said.