An Austrian court could rule Wednesday on whether to reduce or extend the prison sentence of right-wing British author David Irving, jailed in Vienna on charges of denying the Holocaust. Vienna's highest court is due to take up the matter at 8:15 Wednesday. A decision on whether to extend, reduce or uphold Irving's three-year prison sentence could be announced later in the day. In February, another Vienna court sentenced Irving to three years behind bars under a 1992 law, which applies to "whoever denies, grossly plays down, approves or tries to excuse the National Socialist genocide or other National Socialist crimes against humanity in a print publication, in broadcast or other media." The law calls for a prison term of up to 10 years. During his one-day trial, Irving pleaded guilty to the charge of denying the Holocaust but maintained he never questioned it in the first place. Both the defense and the prosecution appealed the sentence. In September, Austria's highest court upheld Irving's conviction. Irving has been in custody in Austria since his November 2005 arrest on charges stemming from two speeches he gave in Austria in 1989 for which he was accused of denying the Nazis' extermination of 6 million Jews. He has contended that most of those who died at concentration camps like Auschwitz succumbed to diseases such as typhus rather than execution. Irving is expected to be present at Wednesday's hearing, his lawyer, Herbert Schaller, told The Associated Press. Schaller, who said he defended Irving in 1989, replaced Irving's previous lawyer, Elmar Kresbach, several months ago. "The defendant expects that, based on the content of the files, the prosecution's appeal seeking to increase the three-year sentence won't be granted," Schaller said, adding he was hopeful Irving's appeal to decrease his sentence would be successful and that he would be released.