High Court rejects ICAC's bid to investigate Crown prosecutor Margaret Cunneen

The NSW ICAC has lost its bid to investigate Crown prosecutor Margaret Cunneen which may have implications for past corruption inquiries like those involving Eddie Obeid, reports Michaela Whitbourn.

A landmark High Court ruling on the powers of the NSW Independent Commission Against Corruption has "destroyed" a major part of the watchdog's jurisdiction and could lead to corruption findings against previous targets of inquiries being overturned, a former judge and ICAC commissioner has warned.

David Ipp, QC, who presided over historic corruption inquiries into Labor figures including Eddie Obeid and Ian Macdonald, said Parliament should intervene to give the commission back its powers "but whether it will is open to question".

The High Court ruled on Wednesday the ICAC had no power to investigate Crown prosecutor Margaret Cunneen, SC, over allegations she perverted the course of justice. The decision, which gave a narrow interpretation to one of the definitions of "corrupt conduct" in the ICAC Act, has far-reaching implications for past and future corruption inquiries.