A former Papua New Guinea Chief Justice has described as strange a law change, allowing cabinet to determine how to apply the death penalty.
Parliament has reactivated the death penalty and toughened new sentences ina bid to counter violent crime.
The new law allows for five types of execution - hanging, lethal injection, deprivation of oxygen, firing squad and electrocution.
Sir Arnold Amet says to vest the determination of method to be used in each case with the National Executive Council runs foul of the constitutional separation of powers.
"I'm sure the judges too will be concerned about a usurpation of judicial power. If you're going to make this law then you either have one method prescribed for all circumstances and the judiciary, it doesn't even decide that particular methodology - it'll decide there is death and the methodology is already decided by the law."
Sir Arnold Amet says he expects this aspect of the law change to be constitutionally challenged.