The NSW Ombudsman is reviewing the powers police have to move drunk people out of public places, two years after tougher laws were introduced.

In June 2011, the Law Enforcement Act was amended giving NSW police greater power to force drunks from public places and ban them from returning for a specified period.

The ombudsman's office says the changes were aimed at "reducing alcohol-related violence and antisocial behaviour, particularly in entertainment districts, and reducing the impact the conduct has on emergency health services".

Before the amendments were introduced, "move on" directions could only be issued to groups of three or more or those whose "behaviour was likely to cause injury to any other person or persons or damage to property, or otherwise gave rise to a risk to public safety," a document from the ombudsman's office says.

Police can now expel from public places those whose behaviour is considered disorderly.

The NSW ombudsman has launched a review into the effectiveness of the extra powers and is looking for feedback from the public.

"The new law can be an effective tool for police to manage a very widespread and growing social problem," NSW Ombudsman Bruce Barbour said.

"But we need to ensure safeguards are being met and that the new powers are being used as intended."

Mr Barbour said concerns had been raised in parliament that the laws could be used to target disadvantaged groups, such as the homeless, the mentally ill and the Aboriginal community.

"Our review will examine whether the legislation has been implemented fairly and effectively, both from the perspective of police and those who are moved on," Mr Barbour said.