Australian counter-terrorism police raided two homes in New South Wales connected to the man accused of the Christchurch mass shootings.

The home of Brenton Tarrant's sister in Sandy Beach, near Coffs Harbour, was raided about 8.30am local time on Monday.

The counter-terrorism officials then stormed a second house at Lawrence, near Maclean, north of Coffs Harbour.

"The primary aim of the activity is to formally obtain material that may assist New Zealand Police in their ongoing investigation," the Australian Federal Police and NSW Police said in a joint statement.

Officers also re-iterated to local media the fact that Tarrant's family continue to assist police with their inquiries.

#BREAKING: Police are raiding the Sandy Beach home of Brenton Tarrant's sister. #9News pic.twitter.com/JebNEQt0El

— Nine News Australia (@9NewsAUS) March 17, 2019

"The community can be assured that there is no information to suggest a current of impending threat related to these search warrant," police said in a statement.

Tarrant's mother and sister have been moved to a safe house by police.

His father, Rodney Tarrant, in 2010 died at the age of 49, from lung cancer.

"We're all gobsmacked, we don't know what to think," Tarrant's 81-year-old grandmother Marie Fitzgerald, told Australia's 9News in an interview.

"The media said he's planned for a long time, so he's obviously not of sound mind, I don't think."

Tarrant's uncle, Terry Fitzgerald, apologised to the families of the dead and injured in New Zealand. "We can't think nothing else, just want to go home and hide," he told 9News.