People living on Sydney Harbour's foreshore have been asked to hand over any CCTV vision they might have of a fatal crash between two yachts.
Emergency services were called to Darling Point about 6.30pm on Friday before a man with critical chest injuries, believed to be in his 50s, was pronounced dead.
Nine people were on board one of the yachts, while four were on the other.
Police investigating the crash are calling for witnesses to come forward and are hoping foreshore residents might have CCTV of the incident, or there could be on-board footage from other boats on the water at the time of the crash.
Both skippers were taken for mandatory testing, although police did not reveal if drugs or alcohol were believed to be a factor in the collision.
The boats were not racing each other but were attempting to manoeuvre around the same marker, police said.
The Royal Australian Naval Sailing Association confirmed the dead man was on board a boat racing in one of its twilight events.
Association membership is not exclusive to former navy personnel and can be taken up by "anyone with a passion for sailing", according to the group's website.
The crash occurred shortly before the start of the Cabbage Tree Island Race, the last offshore race contested by entrants in the annual Sydney-Hobart yacht race, which begins on Boxing Day.
The Cruising Yacht Club of Australia, which berthed one of the boats involved in the incident, said police used its facilities while they conducted interviews.
"There was a tragic accident on Sydney Harbour in which a crew member was killed when two boats participating in races unconnected with the CYCA collided," a club statement read.
