A father and son who were volunteer lifesavers have drowned while trying to rescue a tourist swept out to sea off the Australian state of Victoria.

The boat carrying Ross Powell, 71, and his son Andrew, 32, overturned as they tried to reach the man near limestone stacks known as the Twelve Apostles.

The 30-year-old tourist was winched to safety by a rescue helicopter along with a third lifesaver from the boat.

Australian PM Scott Morrison paid tribute to the Powells.

“Surf lifesavers are selfless and brave,” he said on Twitter.

“We thank them all for their service and extend our deepest sympathies to Ross and Andrew’s family and friends.”