Cunneen's ICAC win raises questions

Questions are being asked about the scope of the NSW corruption commission with the highest court in the land ruling it doesn't have the power to investigate top silk Margaret Cunneen.

The high court on Wednesday ruled by 4-1 majority that allegations raised by ICAC, namely that Ms Cunneen had perverted the course of justice, were not corrupt conduct as defined in the ICAC Act.

The watchdog had accused the top prosecutor of advising her son Stephen Wyllie's girlfriend, Sophia Tilley, to fake chest pains at the scene of a car crash in May 2014 to avoid a blood alcohol test.

ICAC brought the matter to the High Court, arguing an earlier ruling prohibiting it from investigating Ms Cunneen fundamentally affected its capacity to hold investigations into corrupt conduct.

In December last year the corruption watchdog announced it would hold off releasing reports on high-profile probes - operations Credo and Spicer - due to the ramification of the judgment.

With the High Court siding with Ms Cunneen it is unclear what will happen to the reports and their findings.

Acting NSW Premier Troy Grant said the government would review the decision, while the commission said it would comment publicly in "due course".