An Australian investigation team believes it has found the aircraft flown by the last two Australian Defence Force members missing in Vietnam.
Flying Officer Michael Herbert and Pilot Officer Robert Carver disappeared without trace in 1970 while on a bombing mission.
The Defence Department says a recovery team sent into the region a week ago found what it believes to be the wreckage of their Canberra bomber in thick jungle in a remote area near the Laotian border.
While no human remains were found, a number of military artefacts have been discovered including a club badge which was unique to RAAF's No 2 Squadron.
The Minister for Defence Science and Personnel, Warren Snowdon, said the team had spent a week in the isolated province gaining information and hiking in to the wreck site.
"These brave airmen gave their lives in the service of their nation and locating the crash site is an important step in accounting for them, " he said in a statement.
"Relatives of the two crewmen have been advised of the discovery and Air Force will continue to keep them updated."
Mr Snowdon praised the team's use of innovative modelling techniques to narrow the area of interest.
He said the expertise of the Army History Unit in supporting the Air Force investigation was also priceless.
"Invaluable assistance has also been given by a number of former North Vietnamese and Viet Cong soldiers and their commanders, as well as many local villagers, and their compassion and commitment in assisting us is humbling," he said.
Mr Snowdon said the next step would be an archaeological dig to confirm whether there were any human remains at the site.
Families elated
Jim Burke from Operation Aussies Home called the families of the men to let them know the crash site had been found.
"Making those calls to them last night was super," he said.
"When they got the news, they were quite elated, dumbfounded, surprised.
"What the family members firstly want to know is the loss incident circumstances where their kin were killed.
"The next thing they want to do is to recover remains."
Neil James from the Defence Force Association says it could be a very significant discovery.
"What's always been the problem with this one is they weren't quite sure where the plane went down and indeed how it went down and whether the crew were able to eject when it was hit, if indeed it was hit or whether they were rendered unconscious when the aircraft was shot down and were in it when it crashed," he said.
"There's a large number of unknowns about this incident."