The top court in Singapore has thrown out the appeal of death row inmate Kho Jabing, a Sarawakian who was convicted in a murder-robbery case.

Jabing had won a stay on his sentence hours before he was to be executed in November 2015 but the latest court verdict has closed all doors for him as Singapore President Tony is expected to sign off on his execution order any time.

He was initially sentenced to death in 2010 for the murder of a Chinese a national during a robbery attempt. Following the amendments to the mandatory death penalty in 2013, Jabing was re-sentenced to life in prison.

However, the Singapore Court of Appeal upheld his capital punishment in January 2015 with a 3-2 split verdict. He won a last minute reprieve in November when his lawyer launched a criminal motion to reduce his sentence.

Following this the Court of Appeal granted a stay of execution so that his lawyer could prepare his case afresh.

However, on Tuesday, the five-judge Court of Appeal unanimously denied the review, setting up a seemingly irreversible course that leads Kho to the gallows.

The prosecution case is that Kho and fellow Sarawakian Galing Anak Kujat killed construction worker Cao Ruyin during a robbery attempt in Geylang Drive. The prosecution said Kho hit his victim's head with a log, cracking open the head.

The apex court rejected Kho's appeal for clemency saying the murder revealed complete disregard for human life. "The sheer savagery and brutality displayed by (Kho) shows that during the course of the attack, (he) just simply could not care less as to whether the deceased would survive although his intention at the time was only to rob," the verdict said.