'Thieves' blamed for crash

A critically injured teenage motorcyclist was being chased by would-be thieves in a four-wheel-drive vehicle before he crashed into a pole in Gosnells, his family said yesterday.

Kyle Willems, 19, remains in intensive care in Royal Perth Hospital almost two weeks after crashing his yellow Suzuki off-road motorcycle at a Tonkin Highway intersection.

Police are trying to work out what happened to Mr Willems as his family posted confronting images of him in hospital in the hope it will encourage someone to come forward.

Mr Willems' mother said her son and a friend were walking their motorcycles along Tonkin Highway on the evening of September 17 and within minutes her family's lives "made a change for the worst".

Mr Willems' friend, who does not want to be named, claims a white 4WD stopped in front of them as they walked north on the highway towards the Corfield Street exit.

The 4WD did a U-turn, pulled alongside and a passenger allegedly threatened them saying: "Pull over. Us five boys are going to bash you and take your bikes."

Mr Willems rode off in a bid to escape, with the 4WD allegedly chasing him.

He crashed seconds later on a roundabout at the intersection of Tonkin Highway and Corfield Street about 10.20pm.

The 4WD occupants, believed to be in their teens or early 20s, did not stop to help.

The injured teenager's friend said the 4WD was an old-style LandCruiser with a black bull bar, black snorkel on the driver's side and roof racks. Mr Willems' grandmother Ann has posted a Facebook message on behalf of his mother, revealing he was still fighting for life and thanking everyone for their support.

She said her son and his friend had been waiting for her to collect them and he started riding the off-road bike only to try to flee a pursuer.

Anyone with information is urged to call Crime Stoppers on 1800 333 000.