A Maidstone superbike rider has undergone surgery for multiple injuries after being involved in a crash with a safety car.

Steve Mercer, 36, was involved in the collision during a qualifying race for the Isle of Man TT on Wednesday, on an evening where fellow rider Dan Kneen was tragically killed in a separate incident.

He was flown by air ambulance to Nobles Hospital on the island before subsequently being moved to Liverpool where he remains in a "critical but stable" condition.

Race organisers have since launched an investigation into how the crash happened, while safety rules have also been changed to ensure races stop entirely whenever there is an incident on the course.

Mercer's wife Caroline said on Friday morning: "Steve had surgery early Thursday morning for pelvic and leg injuries which went as well as the doctors could have hoped at this stage.

"Other injuries include a broken ankle, heel, T12 vertebrae, a fracture to his larynx and damage to his neck which means he’s not currently able to breathe for himself without support.

"They’re keeping him heavily sedated most of the time to make him more comfortable whilst he recovers from his injuries."

Following the incidents, clerk of the course Gary Thompson said plans to change the track's emergency procedures would be implemented "with immediate effect".

He added: "A red flag instruction will apply to the entire TT mountain course irrespective of where that incident has occurred.

"There will be no movement on the TT mountain course by any rider until the incident has been cleared, regardless of how long that incident may take to clear.

"The riders will only be permitted to move in course direction under the control of travelling marshals at the front and rear."

Since the crash, the sport has united to send wishes of recovery to the Kent star, who has recorded 16 top-20 finishes at the TT and has lapped the course at some 129mph.

A spokesperson for his team, Jackson Racing, said: "Our thoughts are with Steve, Caroline, Daniel, Alex and family."

Mrs Mercer added in a Facebook post: "Thank you so much to everyone who has helped us to get over to him so quickly and for the hundreds of messages of support we have received.

"I have been reading some of your messages out to him to let him know everyone is rooting for him to get better."