SINGAPORE - The Attorney-General's Chambers said on Wednesday that the lawyers of convicted murderer Jabing Kho had abused court processes in his case, by filing multiple court applications last week in a bid to delay their client's execution.

Lawyers Gino Hardial Singh, Jeannette Chong-Aruldoss and Alfred Dodwell had been in court on Thursday and Friday to argue against his sentence hours before his execution, which had been set for Friday morning.

"This was a case where, after every legitimate avenue for legal challenge had been attempted and exhausted, legal opportunism prevailed," said the AGC in a statement.

Mr Kho, who was executed on Friday afternoon, had brutally killed a construction worker while robbing him in 2008. The victim, Chinese national Cao Ruyin, was bludgeoned on the head with a tree branch. Kho had continued to hit him even though he stopped retaliating after the first blow. His skull was shattered, and he died six days later.

The AGC said on Wednesday that Mr Kho's case had been considered twice by both the High Court and Court of Appeal - once under the old law, and again after the law on the mandatory death penalty for murder was amended in 2012.

In both instances, he had been sentenced to death.

But after his rights of appeal had been exhausted, the apex court gave him a further opportunity to present arguments for his case to be reviewed.

Last week, Mr Singh, Ms Chong-Aruldoss and Mr Dodwell filed three applications in court to argue against Mr Kho's death sentence.

However, said the AGC, "in the conduct of his matter, the actions of (the) three lawyers amounted to an abuse of court processes".

First, they had repeatedly raised old arguments that had either been dismissed by the Court, or withdrawn by Mr Kho's previous lawyer, Mr Chandra Mohan, when the case was heard in court earlier, said the AGC.

Mr Singh had, for example, argued last week that the decision to send Kho to the gallows was tainted by apparent bias as Judge of Appeal Andrew Phang had sat in both appeals in Kho's case in 2011 and 2015.

This was the same argument that Mr Mohan had tried to make before, only to drop it subsequently, the AGC pointed out.

"Mr Singh should have known that it is improper to file a fresh application containing the same ground that had been previously withdrawn," it said.

The five-judge Court of Appeal had pointed this out during the hearing and also held that it was not improper for Justice Phang to have heard both appeals as they were on completely different issues.

The 2011 appeal was against Kho's conviction, and had to do with whether or not he should be found guilty. The 2015 appeal was against his sentence, and had to do with what punishment he deserved.

The AGC also pointed out that Ms Chong-Aruldoss and Mr Dodwell had separately tried to file applications on Thursday to argue that the death sentence imposed on Kho violated the Constitution. It said: "Once again, these arguments were not new, for Mr Mohan had earlier raised them, and the Court of Appeal had dismissed them."

Second, Ms Chong-Aruldoss and Mr Dodwell had also tried to "skirt around the law" by trying to raise their arguments under the civil process, after they had exhausted the criminal process, the AGC said.

"Both should have known full well that this type of collateral attack on a criminal decision was an abuse of the legal process," it added.

Third, Ms Chong-Aruldoss and Mr Dodwell had tried to delay the execution by asking for the hearings on Ms Chong's application and her subsequent appeal to be postponed, the AGC said.

They had said that they did not have sufficient time to prepare for the hearings, however, Mr Dodwell was eventually able to argue the appeal, the ACG added.

"It is a cherished principle in our legal tradition that a legal practitioner must do his utmost to uphold the administration of justice. He must also conduct proceedings before a court in a manner that maintains the fairness, integrity and efficiency of those proceedings," said the AGC.

"The actions of Mr Singh, Mr Dodwell and Ms Chong-Aruldoss are not in keeping with the paramount duty a lawyer owes to the Court. It is wrong for any lawyer to assert that his duty to the client allows the court's processes to be abused."

In a separate statement, the Ministry of Home Affairs noted that "several inaccurate points have been made in relation to the legal process" in the case.

The ministry said that Mr Kho "was given every opportunity" to file appeals, apply for re-sentencing after the laws were amended, and petition the President for clemency.

It was only after the apex court dismissed his applications that his sentence was carried out on the date which had been fixed, said the MHA.

It added: "The lawyers' reasons were ostensibly that they were going to make new arguments. In fact there were no new arguments. It appeared that the sole purpose of the applications was to try and delay the execution which had been set for 20 May 2016."