Papua New Guinea's opposition says attempts by the Prime Minister to quash an investigation by the Ombudsman Commission involving his finances have damaged the integrity of his office.
Sir Michael Somare's lawyers have applied to the court to quash the investigation into his alleged failure to properly lodge a series of personal financial returns since 1992.
The deputy leader of the opposition, Bart Philemon, says the Prime Minister's failure to comply with the rules breaches the Leadership Code.
He says they have grave concerns over Sir Michael's attempts to avoid investigation.
"The fact that he's going to the court to bar the Ombudsman Commission from continuing to investigate and refer him to the Public Prosecutor, simply because of his not complying with the organic law, I can't understand the logic behind that at all, because we are all responsible to our requirements under the Leadership Code."
Bart Philemon says Sir Michael's handling of the recent Finance Department inquiry, and the Taiwan diplomatic cash scandal, are further examples of a lack of transparency.