A convicted murderer given extra time in jail for a serious assault on a fellow prisoner has seen his double sentence upheld by the Court of Appeal.

This means that in theory, 36-year-old Antoine Anderson could remain in Westgate prison until the year 2031.

Already jailed for the Boxing Day, 2007 gun murder of Aquil Richardson, Anderson got additional time for inflicting grievous bodily harm on Roger Winston Darrell.

In an August 22, 2011 brawl in the prison eating area, Anderson first beat Mr Darrell unconscious, then kicked him repeatedly in the head.

His victim was left with a broken eye socket, broken nose, fractured teeth and memory loss.

Yesterday, lawyer Gabrielle Stewart attempted to challenge Anderson’s additional sentence on the basis that it was wrong in law.

Her argument that there were no statutory provisions to support imposing extra time to run consecutive to a life sentence was rejected on the basis that Anderson’s sentence is fixed to the date of his eligibility for parole — rather than to his life sentence.

Court of Appeal president Edward Zacca heard the case alongside justices Sir Anthony Evans and Sir Austin Ward.

Accepting Anderson’s appeal would have been tantamount to “no punishment at all” for his crime committed in prison, Mr Justice Ward told the court.

“How can you say someone can behave in the way he did — beat up a person, one of his brother prisoners; he beat him up and almost killed him, and you say he should not receive any separate penalty — how can that be?” he added.

“That would encourage others to beat up other prisoners.”

Mr Justice Ward also noted that Anderson had murdered Mr Richardson after being released on parole while serving time for a previous attack.

In that case, Anderson, in tandem with a group of others, inflicted grievous bodily harm on Dwayne Trott. Their victim was beaten, burned, hacked with a machete and stamped upon.

In his latest court appearance, Anderson remained silent in the dock.

After hearing submissions from Ms Stewart, along with Crown counsel Garrett Byrne, the justices came to a decision in a matter of minutes.

Mr Justice Zacca said: “We are in no doubt that the court has the power to make a sentence consecutive to the period for which parole can be applied for.

“The appeal is dismissed, and the sentence is affirmed.”