According to the United Nations, PNG is ranked 154th out of 180 nations indexed on its corruption scale, prompting some commentators to suggest that the government was not doing enough to fight corruption.
In an address to the Institute of National Affairs last Friday, former Lae MP Bart Philemon said urgent action needed to be taken because corruption had now penetrated the fabric of society.
"The fight (against corruption) must begin at the top, from the Prime Minister down," the Post Courier newspaper today quoted Mr Philemon as telling the INA.
The Post Courier also reported former MP Peter Yama as challenging Prime Minister
O'Neill how far he was willing to take the fight against corruption.
Mr Yama suggested in the news article that corruption was everywhere in the public and private sector and making life difficult for investors and businessmen.
Noting their comments, Prime Minister O'Neill said the government was moving in the right direction in this fight.
"It is no secret that corruption, in all its shape and form, has become systemic and endemic in our country. Both Philemon and Yama have been in Parliament and in government and know that.
"Both men have held positions of influence in government in their time and had an opportunity to contribute to help stem the tide of corruption.
"It's one thing to speak and rumble on in the media on the issue, and quite another to actually step forward and take action," the Prime Minister said.
He said when he was appointed Prime Minister on August 2, 2011, he listed the fight against corruption as one of his top priorities, and set up the SWEEP Task Force to clean up the public sector.