A car enthusiast is recovering from serious leg injuries after a Porsche "surged forward and pinned him against a barrier" in a freak accident at an auction.

The event at British Car Auction in Paddock Wood on Wednesday descended into "chaos", witnesses said, as fellow customers rushed to the aid of the injured man, who was screaming through the pain.

Police and paramedics arrived at the scene, off Eldon Way, at around 11.30am and were joined shortly after by the air ambulance who took the man to King's College Hospital, where he remains in a stable condition.

The auction was swiftly cancelled following the incident, and the venue was placed into lock-down.

One witness, who was among the 200-strong people in attendance, said: "The Porsche was on the ramp and a member of staff was behind the wheel.

"Then the car just surged forward and pinned him against a barrier - nobody knows how or why it happened.

"Everybody was reluctant to criticise the driver - he's never had an accident before.

"The man was screaming and there was a lot of commotion - it was chaos."

A senior manager was then reportedly scrambled to the site, where he is said to have told staff the incident was as bad as anything he had ever seen in more than two decades in the industry.

"It was something that just seemed like a slight mistake on someone's part, that ended up being a tragic incident," the witness added.

"Everyone was very upset."

A BCA spokesperson said: “At approximately 11.30am, there was an incident involving a sale car and two customers at our Paddock Wood centre.

"Emergency services were called and attended the scene and one member of the public was taken to hospital.

"No further details are available at this time.”

A South East Coast Ambulance Service spokesperson said: "We received a call at around 11.20am from British Car Auction off Eldon Way.

"We responded to reports a man had been injured after being hit by a car and sent two vehicles from our base in Paddock Wood.

"The air ambulance also joined us at the scene and the man, who has suffered a serious leg injury, was treated and then airlifted to King's College Hospital."

Kent Police said its investigation has since been passed on to Tunbridge Wells Borough Council's environmental health team.

A council spokesperson said: "We were notified of an incident involving a car and pedestrian at British Car Auction’s site in Paddock Wood on Wednesday, October 3.

"Officers from our environmental health, food and safety team worked with police immediately following the incident and have now taken over the investigation.

"Their inquiries are at a very early stage and they will consider all aspects of the incident before coming to a decision on an appropriate course of action to take."