Brenton Tarrant is appealing against his convictions for murdering 51 worshippers in the Christchurch mosques terror attacks and his life sentence.
A spokesperson for the New Zealand Court of Appeal confirmed to AAP on Tuesday that Tarrant has filed an appeal against his convictions and sentence.
She said no date has been set for a hearing and grounds of appeal were not available.
New Zealand's prime minister accused the mosque gunman, whom she has refused to name since the attacks in March 2019, of re-victimising people.
"His is a story that should not be told and his is a name that should not be repeated and I am going to apply the same rule in commenting on his attempt to re-victimise people," Jacinda Ardern told reporters on Tuesday.
"We should give him nothing."
The Australian man had pleaded guilty to planning and carrying out the massacre and, in a legal first for New Zealand, was sentenced to a lifetime in prison without the possibility of parole.
He was also convicted of 40 charges of attempted murder in his attack on the two mosques, using military-style semi-automatic rifles and filming himself with a head-mounted camera.
A year ago human rights lawyer Tony Ellis wrote in a memo to a coroner that Tarrant told him his guilty pleas were obtained under duress.
He was also allegedly "subject to inhumane or degrading treatment while on remand, which prevented a fair trial".
"He sent me about 15 pages of narrative of how he had been treated since he'd been in prison," Dr Ellis wrote in the memo.
"He said because of how he was treated while he was awaiting trial and afterwards, (that affected) his will to carry on and he decided that the simplest way out was to plead guilty."
Tarrant, who represented himself at his sentencing in August 2020, subsequently disposed of Dr Ellis's services.
The Grafton, NSW, raised man's decision to reverse his earlier pleas and confess his crimes came as a major surprise and meant the matter did not go to trial.
In October last year, chief coroner Deborah Marshall announced there would be a coronial inquiry into the mosque attacks, saying it would allow a "more in-depth investigation into the causes and circumstances of the deaths".
© AAP 2022