Prince William was embroiled in a terrifying road crash on Wednesday (18Nov15) when one of the riders in his motorcade collided with a taxi.

The British royal was travelling back to his residence at Kensington Palace following a public appearance at cancer hospital the Royal Marsden in south west London when the accident occurred.

One of police motorcycle riders who was escorting Prince William's car was struck by a cab and thrown from his bike, which crashed into a nearby garden. The royal stopped to check on the officer but was forced to move on by his security team, according to Britain's The Sun newspaper.

An onlooker tells the publication, "It (the taxi) was making a U-turn. I heard a boom. I saw the officer flying through the air."

The cop was was taken to hospital, and a spokesman for the Metropolitan Police confirmed his "injuries are not life-threatening."