SYDNEY (AFP) - Male doctors are four times more likely to be disciplined for misconduct than female medics, according to a new Australian study which found the biggest cause of complaint was sexual misbehavior.

Researchers at the University of Melbourne analyzed 485 cases where doctors had been found guilty of misconduct and disciplined in Australia and New Zealand between 2000 and 2009.

They found that overall about six in every 10,000 doctors were disciplined in Australia and New Zealand each year by a tribunal with the power to deregister them, with male medics making up the overwhelming majority of cases.

When the figures were adjusted to take into account that there are fewer female doctors and they work fewer hours on average, male doctors were found to be four times more likely to be disciplined than their female counterparts.

Obstetrician-gynaecologists and psychiatrists had the highest rate of disciplinary action, followed by general practitioners, the study published in the Medical Journal of Australia showed.

Doctors were most commonly cited for sexual misconduct (24 percent), followed by unethical or illegal prescribing (21 percent). Eight percent of cases related to the death of a patient.

Lead researcher Katie Elkin, from Melbourne's School of Population Health and Law School, said she had been surprised at the gender difference.

She said in the majority of cases, the patient suffered no physical or diagnosed psychiatric harm.

"These findings indicate that boards and tribunals interpret their public protection role fairly broadly," Elkin said.

"They were often prepared to sanction doctors irrespective of whether or not the misconduct had resulted in harm to a patient. What this suggests is that regulators are not sitting back -- they are trying to be proactive when professional misconduct poses risks to the community."