The Papua New Guinea ombudsman commission has referred a supreme court judge, Justice Mark Sevua, to the public prosecutor for alleged misconduct in office.
This marks the first time that a judge has been referred for investigation.
The chief ombudsman, Ila Geno, has told the Post Courier newspaper that Justice Sevua used the official letter head of the supreme court in a private matter pertaining to his wife's university education.
The judge is alleged to have threatened to have the university dean deported.
The allegation relates to section 27 of the constitution which calls on leaders not to place themselves in a position in which they could have a conflict of interest.
Mr Geno says the investigation will go ahead because the commission is not satisfied with the explanation given by Justice Sevua.