A corruption watchdog says an investigation into allegations of bribery and kickbacks at public authorities and local councils across New South Wales has uncovered widespread corruption.

The Independent Commission Against Corruption (ICAC) has been investigating claims that staff from a number of councils accepted gifts from suppliers to encourage them to keep placing orders with their companies.

The commission's report found it was common practice in some places - with gifts including iPads, vouchers, clothing and holidays.

Although the investigation only looked at 15 local councils, and the then Roads and Traffic Authority, the report has made corruption recommendations that apply to all councils, stating that the problems are systemic.

The commission also made corrupt conduct findings against 41 people.

It will forward the findings of its investigation to the Director of Public Prosecutions this week, recommending that nine of those involved face charges.

The state's acting premier Andrew Stoner says ratepayers will be shocked by the corruption watchdog's findings.

He says the Government is concerned by how frequently matters involving local council workers are coming before the ICAC.

"I think it's a real shock to ratepayers to learn the extent of corruption in some councils in NSW," he said.

"The Government will respond in terms of closing any loopholes in our local government legislation that has enabled this to occur in the past."