The AFP revealed that after a five year long investigation Sydney based Radiance International Pty Ltd, and its related group of companies, had conspired to pay bribes to public officials in Nauru, as it sought access to the island's phosphate resources.
The investigation uncovered the payment of more than $AU100,000 in bribes.
The jailed man, who had pleaded guilty in February, was a director of Radiance International and had been involved in a number of instances of bribery between August 2015 and July 2017.
AFP Assistant Commissioner Northern Command, Lesa Gale, said the complex three-year investigation reflected Australia's commitment to taking action against foreign bribery.
"The AFP investigation showed that a small country, with a population of just 10,000 people, had its primary resource illegally exploited by an Australian-based company."