Death row inmate Iskandar Rahmat had asked the High Court for a disciplinary tribunal probe into his six-lawyer trial defence team because he was unhappy that they had failed to prolong his trial by all means possible.

The former police officer, now 41, was convicted and sentenced to death in 2015 for a crime that came to be known as the Kovan double murder.

In dismissing Iskandar's application for a probe, the High Court noted that his dissatisfaction appeared to have arisen because the second tranche of the trial was vacated as he was found guilty after the first tranche.

"Mr Iskandar's true discontentment, it seemed, was that the trial defence team had not prolonged his trial by use of all means imagined," said Justice Valerie Thean in judgment grounds released last Friday.

Justice Thean pointed out that a lawyer's overriding duty is to the court and he is duty-bound to conduct a case most advantageous to the client but subject to "the interests of justice, public interest and professional ethics".

She noted that the professional conduct rules require the trial lawyer to do his best to "avoid unnecessary adjournments, expense and waste of the court's time; and assist the court in ensuring a speedy and efficient trial and in arriving at a just decision".

In 2013, Iskandar stabbed to death a 67-year-old businessman at his home.

He also stabbed the businessman's 42-year-old son, who chanced upon the crime and ended up being dragged under the getaway car Iskandar was driving.

In 2017, Iskandar's appeal was rejected by the apex court, which held that the key fact was that he had turned aggressive and intended to cause death.

His petition for clemency against the death sentence was also rejected by the President last year on the advice of the Cabinet.

Iskandar then filed a complaint against his lawyers in June last year.

The Law Society said an inquiry committee had probed the case and recommended that no further action was necessary.

Its governing council accepted the recommendations.

After the Law Society turned down his complaint, Iskandar applied to the High Court for a review of the council's decision and an order for the Law Society to apply to the Chief Justice for a disciplinary tribunal to probe the case.

Justice Thean, who heard and dismissed this application last October, said in judgment grounds that when looked at as a whole, "there was no prima facie case of ethical breach or other misconduct by the six-member trial defence team" that justified a formal investigation and consideration by a disciplinary tribunal.

Iskandar's case against the trial defence team was framed as a lack of diligence, a failure to keep him informed on the progress of the case and to explain developments in his case, a failure to follow his instructions, a failure to advance his case using all legal means and a failure to pursue all reasonable defences, said the judge.

But the evidence showed that at each point, the trial defence team had rendered advice, and sought and obtained the relevant instructions, she added.

"It is also clear, from the analysis above, that the various exhibits, witnesses, and evidence, now emphasised by Mr Iskandar, were not relevant to his defence at the trial," said Justice Thean.

"To the contrary, both the prosecution and trial defence teams were praised for 'their highly professional attitude and their full cooperation with the process of justice' by the trial judge," she added.

"Such professionalism is indispensable to the sound administration of justice; without it, the legal profession will be unable to play its part in upholding the rule of law," said Justice Thean.