Dr. Sean Buckingham is serving a seven-year prison sentence following his 2007 convictions for drug trafficking and sexual assault. (CBC)

A lawyer representing a notorious St. John's doctor suggested Wednesday that Sean Buckingham's mental health may have been responsible for drug trafficking and sexual assaults.

An independent tribunal struck by the College of Physicians and Surgeons of Newfoundland and Labrador postponed a hearing about possible sanctions against Buckingham, after lawyer Bill Collins informed them he is considering an appeal of the physician's convictions.

Buckingham was convicted in December 2007 of 12 charges in a Newfoundland Supreme Court trial that exposed how he traded prescription narcotics for sex. A month later, Buckingham was given a seven-year prison sentence.

The college has asked the tribunal to consider sanctions against Buckingham, who voluntarily surrendered his medical licence in 2005, when he was arrested. The tribunal may consider fines or even removing Buckingham's name from the registry of physicians, in effect stopping his medical career altogether.

Collins has not yet decided whether to appeal the conviction, but told reporters that Buckingham's mental health is an issue that could be raised during an appeal.

Collins described Buckingham as having bipolar disorder. "This has been a longstanding diagnosis," said Collins, noting that the issue was raised during the trial.

"There are situations where people have not been convicted because they were mentally ill, but it depends on the degree of the impairment. And that is exactly what we are looking into," Collins told reporters.

Collins said he will travel next week to New Brunswick, where Buckingham is imprisoned.

Collins said he will be consulting with physicians who knew Buckingham before he was charged, and with two psychiatrists in New Brunswick.

The tribunal postponed its work until Oct. 28.

Collins said he wasn't prepared for Wednesday morning's hearing because he only learned about it in the news last week.

The college's registrar, Dr. Robert Young, said the college cannot be held responsible for that.

"We didn't know he was doing [this], so we wouldn't have informed him," Young said after the hearing.

"I guess we were equally surprised when we learned that this was taking place, and that we would be asked this to adjourn the hearing today."

The Royal Newfoundland Constabulary said during the trial that Buckingham had played a key role in the illicit trade of OxyContin, a powerful and addictive narcotic, in the St. John's area in the years leading up to his arrest.