NZ First leader Winston Peters is calling for a commission of inquiry into the way RSA attack survivor Susan Couch has been treated by ACC.
Ms Couch was left partially paralysed with brain injuries after the December 2001 attack at the Panmure RSA by William Bell, who killed three others.
Bell was on parole and the Corrections Department is paying her $300,000 for exemplary damages after an 11-year court battle, but ACC hasn't given her any compensation because she is on a benefit.
Mr Peters says ACC regulations must be changed so Ms Couch and other victims of serious crimes can be compensated.
"It is outrageous that ACC will not pay compensation to Ms Couch because she is on a social welfare benefit," he said.
"We need a full royal commission of inquiry to assess the failings of ACC in this regard so regulations can be changed."
Mr Peters says "any right-minded person" can see Ms Couch should be entitled to ACC compensation.
Ms Couch sued Corrections for $500,000, claiming Bell wasn't properly supervised by the department.
Her lawyer, Brian Henry, also says she should be compensated by ACC and is campaigning for a law change.