A motorcycle rider was injured after his vehicle crashed into a gutter in Werrington Downs on Sunday.
Police said the accident happened in Bungalow Parade at about 7.30pm.
They said the rider was flung from his bike and appeared to have sustained several bone breakages.
He was taken by ambulance to Westmead Hospital.
Police said if anyone had any information that could assist them with their investigation, please contact St Marys detectives on 9677 7499 or Crime Stoppers on 1800 333 000.