Witness C has filed an appeal against his conviction and sentence for lying at the double-murder trial of David Tamihere 27 years ago.
Papers were filed yesterday with the Court of Appeal by a lawyer on behalf of Witness C.
The grounds cited were that "the verdict was unreasonable and not supported by the evidence" and the "sentence is manifestly excessive".
The secret jailhouse witness gave what the prosecutor in the perjury trial called "powerful" evidence in the 1990 jury trial, which resulted in Tamihere being found guilty of killing Swedish tourists Urban Hoglin and Heidi Paakkonen.
Tamihere, who described Witness C's perjury convictions as a "major" moment in his case, has always professed his innocence. Tamihere spent 20 years in jail before being released on parole.