Sqn Ldr Daniel Cremin, 25, died in 1942 when his plane came down over Cornwall.
Mark Cremin, said a sealed coffin of his father's remains was sent to his family and buried in Wiltshire but it "may have just been sandbags".
Sqn Ldr Cremin's bones have now been interred in his original grave after being discovered last year.
Following the discovery of his remains an inquest will be held. It is due to open on Monday in Truro.
Sqn Ldr Cremin was an Australian pilot who was awarded the Distinguished Flying Cross for his bravery during the siege of Habbaniya in Iraq, shortly before he died.
He served in the Middle East before being transferred to 66 Squadron.
On 24 March 1942, he was on operational training over Cornwall when his Spitfire collided with another Spitfire flown by Australian, Sergeant William Norman. Both men were killed.