Prime minister Scott Morrison has confirmed the man taken in custody over the New Zealand mosque shooting is Australian-born and slammed the attack as “callous, right-wing” terrorism.

In a press conference in Sydney, Mr Morrison said Australian authorities had launched their own investigation into alleged shooter Brenton Tarrant.

“As family members with our New Zealand cousins today, we grieve, we are shocked, we are appalled, we are outraged, and we stand here and condemn absolutely the attack that occurred today by an extremist, right-wing, violent terrorist,” Mr Morrison said.

“I particularly want to express my sincere prayers and thoughts for those New Zealanders and Australians of the Islamic faith today who have been the subject of the vicious and callous right-wing, extremist attack.”

Mr Morrison said while New Zealand authorities were leading the investigation, Australian agencies had launched their own investigation into Mr Tarrant.

“We will keep Australians safe in every way possible we can and we will work with our partners in the region, our family in the region of New Zealand to do everything we can to support them,” Mr Morrison said.

“I can confirm the individual that was taken into custody is an Australian-born citizen and obviously that element of the investigation Australian authorities are involved in.”

He said Australia’s terror threat had not been upgraded, but said Australian’s should be “alert and aware” to the “horrible, sickening” events.

The prime minister said his heart went out to the Islamic community in Australia and New Zealand.