The Papua New Guinea Foreign Minister, Sam Abal, says the attempted murder of the Chief Ombudsman, Chronox Manek, shouldn't go unchallenged.
Mr Manek was shot outside his home last Friday, but returned to work by the middle of this week.
Mr Abal says many in PNG will be totally outraged by the attack.
He has appealed to the people not to attack leaders, such as Mr Manek, who are dealing with sensitive matters.
Mr Manek had been conducting a number of investigations into prominent Papua New Guineans, including the Prime Minister Sir Michael Somare.