A West Australian paediatrician has been found guilty of unprofessional conduct by a tribunal by providing a written note to the mother of twin boys recommending that both parents use corporal punishment on their sons.

Consultant paediatrician David Evan Roberts was taken to the State Administrative Tribunal by the Medical Board over his treatment of the boys, whom he diagnosed with Attention Deficit Hyperative Disorder (ADHD) in 2008 when they were eight years old.

A hearing at the tribunal was told that after a consultation in 2010, Dr Roberts gave the boys' mother a note that said: "I recommend to your husband, that he beat (physically) each and any of your our (sic) sons who swear and offend his wife (that is Mother) ... to within in (sic) an inch of his life."

The Medical Board alleged the note had the potential to lead to the boys being subjected to corporal punishment, which could worsen their behaviour and contribute to the development of psychological or psychiatric problems.

However, Dr Roberts denied the note was a recommendation for the parents to beat the children.

He maintained he was speaking metaphorically, and that the note was a recommendation for the father to take an active role in defending his wife's honour, if the boys were physically and verbally aggressive towards her.

The note also referred to one of the boys as "a sooky la la" who needed to "toughen up, Princess".

Mother thanked doctor for care and support of children

Dr Roberts told the tribunal he deeply regretted the wording of the note, which "showed an appalling lack of judgement".

However, he pointed out that in 2011, the mother wrote to him, thanking him for his care and support of her children.

In its findings, the tribunal rejected Dr Roberts' explanation and found that "the note contained what the practitioner knew, or should have known, could have been taken as a recommendation that the patients' parents should use corporal punishment to discipline the patients".

"This put the patients' health, safety and welfare at risk," the tribunal said.

"The tribunal regarded the practitioner's conduct ... as being of a lesser standard than that which is expected of him by the public and by his peers."

The tribunal also found that the note, and another given to the mother, were "derogatory" of one or both of the boys.

However, it dismissed a range of other allegations against Dr Roberts, including professional misconduct and unsatisfactory professional performance.

The action against Dr Roberts was taken by the Medical Board after an anonymous letter was sent to another doctor, Gervase Chaney, in 2012.

The letter said: "You say 'no' to smacking children. Please find a note presented to a parent of 2 boys, who went to seek behavioural advice from one of your colleagues."

The tribunal has not yet issued a penalty for Dr Roberts.

The ABC has been told he contests the findings made against him and intends to appeal against them.

Editor's note, January 9, 2019: This story has been amended to further clarify the nature of the findings made against Dr Roberts.