In carriage: Pippa Middleton. But car snaps are being probed by Paris cops

Pippa Middleton was plunged into hot water by a police investigation into a series of photographs showing her being driven through Paris by a man apparently brandishing a gun.

Prince William’s sister-in-law was pictured in the French capital after attending a lavish fancy dress party to celebrate the 30th birthday of fashion entrepreneur and aristocrat Vicomte Arthur de Soultrait.

The images show the driver of the Audi convertible pointing what seems to be a pistol at the photographer.

De Soultrait can be seen in the back of the vehicle sporting a blue baseball cap while Miss Middleton, wearing a pair of dark glasses, is in the front.

A police source said: “We saw the pictures on the internet and we expect to receive more information on the subject. We are looking into it.”

If French authorities consider there is sufficient evidence for a prosecution, Miss Middleton and Mr de Soultrait could be summoned to give evidence.

The 28-year-old sister of the Duchess of Cambridge, who lives in swanky Mayfair, was reportedly being driven to the Gare du Nord station to board a Eurostar train to London on Saturday when the photos were taken.

The previous evening, she and other guests attended de Soultrait’s exclusive celebration entitled “Le roi est mort, Vive le vicomte”.

The party saw friends turn out in an array of elaborate period costumes, with Miss Middleton sporting a bright pink and gold number with flared sleeves.

De Soultrait is the man behind the Vicomte A label which produces preppy clothing and sportswear.