Prosecutor Peter Pickering said that after a chief financial officer, appointed to the business in 2013, found various cash deposits had not been banked, Gilles admitted she had handed them to Nanai.
The Agereported that Nanai said Gilles did not know he was taking the money, but that they would share meth every day and he "sent the rest of the money to New Zealand".
Nanai pleaded guilty to the theft of $325,000 between February and September 2013 and Gilles pleaded guilty to false accounting.
The judge noted that Nanai was a "gifted" rugby player and had been diagnosed with low-cognitive functioning.
The Age reported the judge said that although his size may protect him "from physical abuse, others make seek to use it to their advantage".
He told the couple the offences were serious, committed over a sustained period and involved a large amount of money, but that each had the "capacity to lead decent, honest lives" as long as they remained drug-free.