An Australian barrister, Roger de Robillard, says it's unacceptable for his country to get involved in matters of another sovereign nation.
The comment comes after a Brisbane judge ordered all charges against a former Solomon Islands Attorney General Julian Moti be dropped.
Mr Moti had been charged with raping a 13-year-old girl in Noumea and Vanuatu in 1997 but the judge dismissed the case.
The Brisbane court found that Australian Federal Police's payment of 134,000 US dollars to the alleged victim brought the justice system into disrepute.
Mr de Robillard, who has been working in Melanesia, questions Canberra's actions in the region.
"What Moti's case has done now is to expose what's been going on in the South Pacific since at least 1995 that I have knowledge of. In other words Australia should really have no say in who's the Attorney General of countries such as Solomon Islands."
Roger de Robillard