Five die in Sydney harbour crash

Nine others were injured as all 14 people aboard the smaller boat were thrown into Sydney Harbour.

All of the dead and injured - aged between 18 and 31 - were reportedly from the cabin cruiser.

The accident occurred just before 0300 (1700 GMT on Wednesday) in the once-busy commercial port, now mostly used by pleasure craft and ferries.

Conditions at the time of the accident were cold and pitch black, reports the BBC's Nick Bryant from Sydney, and there were scenes of chaos on a nearby wharf as the injured were treated.

Both boats have now been impounded at a police marine area, our correspondent says, while investigators try to make sense of why 14 people were on board a small cruiser in the middle of the night.

Local media is reporting that the boat, which had "Sydney Ship Repair" written on the side, had been stolen.

Four women and one man, aged between their late teens and early twenties, died as their  aluminium half-cabin runabout collided with a fishing trawler about 200m off Bradleys Head, near Taronga Park Zoo, about 2.40am.

The impact tore apart the stern of the smaller, aluminium vessel, which had 14 people aboard - even though it was only desgined to hold a maximum of eight.

The small cabin cruiser had been taken on a joyride. Police and the owners of the boat - Sydney Ship Repair and Engineering, based on Goat Island - are skating around the issue of whether the boat was stolen, although both agree it was apparently taken without permission.

Marine Area Command Inspector Glen Finness - who said the runabout was carrying 14 people, but was only meant to take up to eight - stressed it had not been stolen from its mooring.

But he would not comment on whether the owner knew it was missing or knew who had taken it.

He also said the runabout was on a social outing, but couldn't comment on whether it was a party. And he added it was too early to answer speculation that it had its lights off and that the passengers may have been consuming drugs or alcohol.

"They're out doing social activities,'' he said. "That will be part of the investigation.''

He also said the group was "mostly'' from Sydney.