The man accused of murdering 51 worshippers at two Christchurch mosques last year has changed his plea to guilty, according to New Zealand Police.

Last year, Australian citizen Brenton Tarrant plead not guilty to 92 charges, including 51 counts of murder, 40 counts of attempted murder and one charge under the Terrorism Suppression Act, the first time such a charge has been laid inside the country.

But, appearing via audiovisual link from a prison in Auckland, Tarrant plead guilty on all counts at a hearing in the Christchurch High Court on Thursday morning. He is expected back in court in May.

New Zealand Police say Tarrant will not be sentenced until it is possible for all victims who wish to attend the hearing to do so — something that may be delayed by the current pandemic.

The High Court hearing comes as New Zealand goes into lockdown to stop the spread of coronavirus, with only essential services — including courts — allowed to stay open.

Tarrant's admission of guilt also comes just days since the anniversary of the deadly attack, which took place on March 15 last year and was New Zealand's worst mass shooting in modern history.

Under New Zealand law, murder carries a life sentence, and convicted murderers must spend at least 10 years in prison before they are eligible for parole.