Victims who emerge as a result of ongoing inquiries into child abuse won't be able to claim compensation because of the NSW government's reporting cap, the opposition says.

Changes to the victims compensation scheme prevent victims of sexual assault, domestic violence or child abuse from making a claim more than a decade after the crime.

This will leave many victims of historical abuse excluded from compensation, Opposition Leader John Robertson says.

"This is a disgraceful act from the O'Farrell government," he said.

Mr Robertson said the changes would have a major impact on victims who tell their stories to the nationwide royal commission, and the NSW inquiry into historical child abuse in the Hunter Valley.

"This is a low move by the O'Farrell government to avoid paying compensation to child sexual abuse victims who come forward as part of the special inquiry and royal commission," he said.

Mr Robertson said the state government had ignored advice from Legal Aid NSW that the implementation of an eligibility limit would hurt victims of historical abuse.

It said many people would manifest psychological damage after the time limit had passed, and many failed to initially report the crime because of fear, shame or embarrassment or because they were young at the time of the offence.

The laws will also be applied retrospectively, affecting victims of historical abuse with a current claim.

Mr Robertson said 506 child sexual assault victims last year sought compensation more than ten years after the abuse.

In question time on Wednesday, he called on the government to ensure victims of child sexual abuse would not be disadvantaged as a result of the changes to victims compensation.

Attorney-General Greg Smith said the government had announced a range of measures to assist victims of crime, including a new victim support scheme and a victims commissioner.

"We want victims of crime to be given better support and services when they need them most," he said.

He said all existing claims had moved to the new scheme, with the aim of finalising them by 2015.