As ICARE says, you're very fortunate to have had an Australian POW as the relevant authorities of the time always carried out fairly extensive post war investigations into the causes of the crash and its possible location.
The
Australian Archives are I think far ahead of the current British military archival system based at Innsworth in Gloucestershire...where no one except the individual in question or very close relatives are allowed to access personnel files....with written permission of course......pretty stupid when you are talking about events that occured more than 60-70 years ago....and with the distinct possibility that the person in question is well and truly dead....the average age of a second World War soldier is now 91, after all !!!!
Anyway, I'd better hop off my high horse and give you some details..
Here's the website:
www.naa.gov.au
Go to
Name Search...enter the name of the chap, and then select World War Two in the drop down menu or
Category of Records menu...
Have a go and Good Luck to you....!!!!!
cheers,
Andy.