Kumar was charged with perverting the course of justice and was later found guilty. He was acquitted of a second charge of perverting the course of justice.
He was sentenced in the High Court at Auckland in September to a further three years in prison for perverting the course of justice.
In the Court of Appeal today (Thur) Kumar's lawyer Robert Lithgow argued that the original rape trial was not a fair trial because Kumar was not present.
Kumar absconded on bail the night before his trial was due to go ahead in the High Court at Auckland.
Justice Chris Allan decided to proceed without Kumar there, but Mr Lithgow today called into question the amount of preparation and time Kumar's trial lawyer put into the case.
"He just does not spend time because there is no time there available to do these things."
But the Court of Appeal judges, Justices John Wild, Anthony Randerson and Ellen France, today asked why Kumar, who "deliberately absconded" from trial, did not complain about the lack of his lawyer's preparedness before going to trial.
Mr Lithgow said the basis of Kumar's defence - that there was no sexual intercourse, therefore it could not be rape - was not put to the jury by his trial lawyer.
"In this case the jury are the fact-finders and they are not told a thing."
It was also not put to the jury that one of the victims could have been lying when her statement to police and evidence on the stand did not match up, and it should have been, Mr Lithgow said.
"And because Mr Kumar wasn't there to argue with that strategy, the system does not allow a definite way of telling fact-finders what Mr Kumar's defence actually was."
Kumar was present at today's Court of Appeal hearing, sitting quietly towards the back of the room and working through a pile of extensive notes throughout the hearing.
The hearing began yesterday and continues.