Former NSW Labor premier Bob Carr says "everything should be considered", including retrospective legislation, to ensure the Independent Commission Against Corruption retains "robust powers", after a devastating High Court ruling on the scope of its powers.

The ICAC says the four-to-one majority decision of the court imperils some of its most high-profile investigations as well as past convictions flowing from some of its inquiries.

Former NSW premier Bob Carr, who would like to see a more robust ICAC process. Credit:Ryan Osland

Mr Carr said the people of NSW "want a strong ICAC that has got robust powers when it comes to investigating corruption of the governmental political process".

"I think we're all looking to both sides of politics to shake this judgment out and work out what amendments are required," he said.