POLICE closed a Waterfall road for a short time this morning as investigations continue into a fatal crash last week.

About 3pm on Wednesday police attended Mckell Avenue in the Royal National Park following reports a motorcyclist had crashed.

Paul Snepvangers, 58, was found lying on the road next to his bike suffering fatal injuries. About 12.45pm yesterday, police executed a search warrant at an address on the Princes Highway, Helensburgh.

Police seized a Hino flatbed truck police suspect of being involved. A 52-year-old man was taken to Sutherland Police Station where he assisted police with inquiries. He was released pending further inquiries.

About 8am today police closed Mckell Avenue for a short period of time for further examination of the crash scene.

Anyone with information is asked to contact the Metropolitan Crash Investigation Unit or Crime Stoppers on 1800 333 000.