A Sydney filmmaker says he is 100% certain he has found the final resting place of Sir Charles Kingsford-Smith off the coast of Myanmar, or Burma.
The Australian aviation pioneer and his co-pilot Tommy Pethybridge disappeared without trace in 1935 while attempting to break the record for a flight between England and Australia in the Lady Southern Cross.
Nearly 75 years later, Damien Lay believes he has solved what he called Australia's "last great mystery".
He says he and his search team located wreckage of the Lady Southern Cross off the Myanmar coast on 24 February.
The five-day search involved 63 dives and sonar tracking.
Mr Lay told reporters at a news conference in Sydney on Saturday that he found the wreckage under 20 metres of water and mud in a bay on Aye Island.
The plane was a Lockheed Altair and Mr Lay said details recorded in sonar imaging at the site match that of an Altair.
Mr Lay said he would now seek confirmation that the wreck is an Altair from Lockheed in Australia and the United States. He plans to mount a recovery operation in November this year.
In 1928, Sir Charles made the first non-stop flight across the Tasman Sea to New Zealand.