The death toll in the attack on two mosques in the New Zealand city of Christchurch rose to 50 after investigators found another victim as they removed bodies from the crime scenes, the country's police commissioner said on Sunday.

The bodies of the victims in the attack by a suspected white supremacist in Friday's attacks had not yet been released to families because investigations were ongoing, but police were working as quickly as they could to do that, Police Commissioner Mike Bush said at a media conference in Wellington.

Australian Brenton Harrison Tarrant, 28, a suspected white supremacist, was charged with murder on Saturday.

Tarrant, handcuffed and wearing a white prison suit, stood silently in the Christchurch District Court where he was remanded without a plea. He is due back in court on April 5 and police said he was likely to face further charges.

Friday's attack, which Prime Minister Jacinda Ardern labeled as terrorism, was the worst ever peacetime mass killing in New Zealand and the country had raised its security threat level to the highest.

"It is with sadness that I advise that number of people who died in this event has now risen to 50," Bush said.

"As of last night we were able to take all of the victims from both of those scenes. In doing so we were able to locate a further victim."

The body of the 50th victim was found at the Al Noor mosque, where more than 40 people died on Friday after a gunman entered and shot randomly at people with a semi-automatic rifle with high-capacity magazines, before traveling to a second mosque.

Bush said there were also 50 people injured. Thirty-six were being treated in Christchurch Hospital, with two remaining in intensive care, and one child was at a dedicated children's hospital.

Bush said police did not believe that three other people arrested on Friday were involved in the attack. Two men faced charges unrelated or "tangential" to the attack, while a woman had been released, he said.