It is quite easy to see which aircraft are owned or leased, a looksee at the civil aviation register will show that. Just do a search for all aircraft operated by Virgin.
When the list comes up any a/c where the holder is not Virgin Australia will be leased. Though like Qantas Virgin have some shelf companies that own the aicraft and lease to Virgin, these are all easy to spot as their address is the same as the Airline, ie Spring Hill QLD.
http://casa-query.funnelback.com/sea...craft_register