Putting pressure on the Australian government over the Manus Island refugees could come at a cost, opposition leader Bill English has warned.

He was commenting on reports that Australian authorities have turned back four boats carrying 164 asylum seekers trying to get to New Zealand.

The story has broken as Prime Minister Jacinda Ardern takes a tough line over the Australian government's refusal to accept New Zealand's offer to take 150 Manus Island refugees.

She spoke briefly to Australian Prime Minister Malcolm Turnbull at the APEC summit in Vietnam over the weekend and expects to have a more substantial meeting at the East Asia Summit in the Philippines this week.

Ms Ardern admitted on Monday she risked irritating Australia but said it was important to highlight New Zealand's ability to assist.

Brisbane's Courier-Mail newspaper reported on Tuesday Australia's Operation Sovereign Borders had turned back the four boats.

"It can be revealed crime syndicates have tried to bypass Australia's tough immigration measures and attempted to send four boats carrying 164 asylum seekers to NZ," the paper said.

Mr English told reporters the government should take account of what was going on.

"The fact that there's been a story at all, when there hasn't been for a long time, should be an indication to the government that going through this show of putting pressure on the Australian government does have a cost," he said.

"We rely on the cooperation of Australia to ensure people don't head towards New Zealand in these boats, because it's the Australian authorities who see these boats and turn them round."

The Courier-Mail report said it wasn't known when the boats were intercepted or what country they came from.

It said they were turned or towed back to near Indonesian waters.

Acting Prime Minister Kelvin Davis was asked whether he thought the report had emerged as a push back against Ms Ardern's attitude.

"Quite possibly, but we're not responsible for Australia or the decisions they make," he said.
Mr Davis doubted whether any refugee boats could reach New Zealand.

"The whole scenario is a bit of speculation, it wouldn't be easy crossing the Tasman Sea," he said.

"There's a few thousand kilometres of the roughest water in the world."

There are more than 400 refugees at the now-closed Manus Island detention centre who are reported to be without food, water or electricity.

They've been told to move to alternative accommodation but say they're afraid of being attacked by locals.

On Monday demonstrators locked themselves to the gates of the Australian High Commission in Wellington in protest at the plight of the refugees.

 - NZ Newswire