Mark Ciavarella, 57, was allegedly poisoned in his unit in the Congo, in central Africa before his body was tossed into a crocodile infested river.
He had been working at international schools in the country for six years.
His family from Leeton in the New South Wales Riverina region last heard from him in October.
His flatmate and lover has been charged with murder and will face trial in March.
The Department of Foreign Affairs and Trade said it is providing consular assistance to the Ciavarella’s family.
“Owing to our privacy obligations, we are unable to provide further comment,” a spokesperson said.