The underwater hunt for the missing Malaysia Airlines flight MH 370 may be called off as soon as July.
The search spanning 120,000 sqkm has failed to find any trace of the Boeing 777 that went missing in March 2014.
Five fragments of wreckage have washed up in Africa, but that's not enough to convince the Australian Government to spend more than the budgeted $60 million.
Australia's Transport Safety Bureau chief Martin Dolan said there was only 15,000 sqkm of the most likely crash zone left to search.
"Governments have commissioned us to cover up to 120,000 sqkm, we've got about 15,000 sqkm of that to go.
"We are at the point of the search we have to contemplate the possibility we won't find it. The families will be upset, disappointed."
Mr Dolan said that barring any discoveries by July, the search would be stopped.