You can chase him and if you get a court judgment against him in the IK you will be able to enforce same in Australia, but you have to go through the Australian courts to do so.
Regards, David Mond, Insolvency Practitioner for over 46 years. Personal Insolvency Practitioner of the year 2012, Personal Insolvency Practitioner of the year finalist 2013 & 2014 awarded by Insolvency & Rescue Magazine and 2015 finalist for Personal Insolvency Firm of the Year.