A leading group of doctors from Australia and New Zealand is pushing to make it a criminal offence for parents to smack their children.

The Royal Australasian College of Physicians will call for a legal amendment to give children the same protection from assault as others in the community.

The president of the college's paediatrics and child health division, Susan Moloney, said physical punishment could escalate to abuse. ''We know that a significant number of child homicides are a result of physical punishment which went wrong,'' she said.

Research shows it can lead to depression, anxiety, aggression, antisocial behaviour and substance abuse. In Australia it is legal for parents to use corporal punishment on children as long as it is ''reasonable''.