Premier Mike Baird has announced the government will legislate to confirm all past corruption findings by the state's graft watchdog remain valid, including against four prominent businessmen involved in a mining venture over the Obeid family farm, after a High Court ruling put them in jeopardy.

But Mr Baird has stopped short of giving the Independent Commission Against Corruption powers it was seeking in the wake of the decision, choosing instead to ask an independent panel of experts chaired by the former Chief Justice of the High Court, the Hon Murray Gleeson AC QC, to review its powers.

The panel will include Bruce McClintock, SC, who conducted a review of the ICAC in 2005.

The review is likely to determine what findings the ICAC can make in two of its most high profile recent investigations, Credo and Spicer, both of which have been on hold following the High Court decision.

Mr Baird said the legislation, due before parliament next week, would validate the ICAC's actions in the investigations, which examined Obeid-linked company Australian Water Holdings and alleged Liberal Party rorting of donations laws.

The panel's recommendations, if acted on by the government, will then determine whether ICAC can make corruption findings and prosecution recommendations against the people it has investigated.

Mr Baird said the review of ICAC's powers would be delivered to the government by July 10 "so that a second Bill, if deemed necessary, can be introduced later this year".

Last month's High Court decision thwarted the ICAC's bid to investigate deputy senior Crown prosecutor Margaret Cunneen, SC over allegations she advised her son's girlfriend to fein chest pains to avoid a breath test at the scene of a car accident.

That court found the commission does not have the power to investigate private citizens who seek to mislead public officials who themselves do nothing wrong.

This invalidated its findings against businessmen Travers Duncan, John McGuigan, John Atkinson and Richard Poole.

The men were found by the ICAC to have acted corruptly by concealing the involvement of the family of corrupt former Labor minister Eddie Obeid in a coal tenement over their Bylong Valley farm.

The ICAC announced it would agree to court orders declaring invalid findings against the businessmen as a result of the High Court decision.

At a news conference, Mr Baird said the government was taking the action because it wants "the strongest possible watchdog and the best possible outcome."

He described Mr Gleeson as "the best legal mind in the country".

"We're saying to past findings, anyone that has been caught, well, they stand," he said. "In terms of the current [investigations] and future [findings] we need to get it right."