[1] She later worked as the public affairs manager for the Regional Assistance Mission to Solomon Islands (RAMSI).
In February 1997, O'Callaghan broke the story in the Weekend Australian that the Papua New Guinean government had secretly hired foreign mercenaries to fight in the Bougainville Civil War.
The subsequent fallout brought down the government of Prime Minister Julius Chan.
She subsequently wrote a book on the subject, Enemies Within: Papua New Guinea, Australia, and the Sandline Crisis: The Inside Story, in 1998.
[7] O'Callaghan is married to Solomon Islander politician and trade unionist Joses Tuhanuku.