Police are seeking information about a serious crash in East Victoria Park, in which a motorcycle rider was seriously injured overnight.

Officers attempted to stop two motorcyclists on Hayman Road about 9pm, it’s alleged one rider stopped, but the other sped away.

A short time later, police were called to a crash on Kent Street where a 38-year-old man on a Harley Davidson had struck a pole after failing to negotiate a roundabout.

The rider was seriously injured and has received emergency surgery to reattach his severed leg at Royal Perth Hospital.

Major Crash officers are investigating and anyone with information is urged to contact Crime Stoppers on on 1800 333 000.