Transparency International in Papua New Guinea says Sir Michael Somare's most recent term in power will be remembered for the government he headed failing to follow its own rules.
Sir Michael, who remains in intensive care in hospital in Singapore, has been retired from the prime ministerial post by his family.
TI's chair, Lawrence Stephens, says Sir Michael has had a huge personal impact on many people.
He says Sir Michael was one of those who set up the rules under which the country operates but the government he's headed for the past nine years has been ignoring many of those rules.
"So on the one hand his legacy would be the rules that guide democracy that we have, and let's face it, part of that is the freedom for us all to speak, and the other side of it is being involved in a parliament and a government system which tends to have been simply ignoring the laws, of late, or finding ways to avoid following the rules that had been set way back then."