THE level of corruption at Wollongong Council was "without precedent" a sensational public inquiry found yesterday.

Developers, council staff and councillors were caught in a web of sexual and corrupt business relationships for which 11 people would face prosecution for a total of 139 criminal offences.

The commissioner of the Independent Commission Against Corruption, Jerrold Cripps, said it was not uncommon to find cases where multiple layers of management in an organisation had failed to detect corrupt conduct. "But to establish actual corrupt conduct within five levels of a NSW public sector organisation, as has occurred with Wollongong City Council, is without precedent," Mr Cripps said in a statement.

The final report from ICAC, which examined how a culture of corruption inside the council created opportunities for developers to influence planning decisions and make windfall profits, will have ramifications for the way other councils assess developments and could force the State Government to take a bigger role in planning decisions.

But Opposition parties said the Government had escaped any real criticism, despite its role in nurturing close relationships with developers.

Many of the recommendations for prosecution were against ALP councillors and officials or developers who were generous donors to NSW Labor.

ICAC found that early signs of corruption at the council could have been detected if the Department of Planning had made councils record when they overrode their own planning rules to approve developments.

The commission also made 27 corruption prevention recommendations, many of which will have broader relevance to other councils.

Despite that, the Premier, Nathan Rees, said the report proved NSW was a "corruption-resistant state".

"As regrettable … as that whole incident was, today's release of that report demonstrates that we are a corruption-resistant state," Mr Rees said. "And, where it does exist, it does get routed out."