A new study has found that doctors are unlikely to tell patients if there has been a mistake in their treatment because they are afraid of the legal consequences.

Australia has a national standard that encourages full disclosure about problems in medical treatment.

But a University of Melbourne survey of 51 doctors and nurses from around the country found that 90 per cent admitted legal fears were a barrier to open disclosure.

The study's author, David Studdert, says new laws are needed to prevent disclosure information from being used in legal proceedings.

"This is part of a larger project in which we've been trying to understand the laws in Australia that cover this area and our conclusion is that there is a need for law reform in this area," he said.

"And if we don't get the reform it's going to be very hard to get a lot of clinicians on board with this very important part of the health care process."

Mr Studdert says clinicians should feel they can talk to their patients without the threat of legal action.

"We're not suggesting there ought to be immunity as a result of such laws," he said.

"All we're saying is that the specific information that's conveyed in the conversation - that is the open disclosure conversation - wouldn't be used in court or a disciplinary hearing."