EXPERT crash investigators have gathered evidence to see whether a motorcyclist who died in the Royal National Park was hit by a truck.
Paul Snepvangers, of Kirrawee, died last Wednesday while riding in McKell Avenue at Waterfall.
Police and paramedics went to his aid but were unable to help the Sutherland Shire social worker.
Investigators found evidence at the site which suggested a large vehicle had been involved in Mr Snepvangers's death.
They closed McKell Avenue for several hours on Wednesday, and on Sunday to re-examine the scene.
Inspector Steve Blair, commander of the metropolitan crash investigation unit, said public tipoffs had led to the seizure of a Hino flat-bed truck at Helensburgh on Saturday.
"The truck has been recovered; that and the motorcycle are now undergoing forensic examination," he said.
"We've got to thank the community for their assistance with that.
"If there is anybody with any knowledge of the accident at all, please contact Crime Stoppers."
Inspector Blair said police interviewed the owner of a truck, a 52-year-old Helensburgh man, who was released without charge.
Mr Snepvangers's daughter, Jhoanna Parker, has appealed for anyone with additional information about the crash to come forward.
Mrs Parker, of Mortdale, said her family needed to know what had happened.
"We hold no animosity towards the person or persons involved," she said.
"Losing my father, Paul, has been very difficult, but not knowing the truth has been more difficult."
Crime Stoppers: 1800 333 000.