The Green Party is urging the government and New Zealand authorities to do everything possible to bring anti-whaling activist Pete Bethune home.
Mr Bethune was arrested in Tokyo on Friday - he had been on the whaling vessel the Shonan Maru 2 for nearly a month, after boarding it, intending to make a citizen's arrest of the captain.
He took the action after his protest boat the Adie Gil was sunk, in a collision with the Japanese ship.
Green Party co-leader Metiria Turei says it's time the government stepped in to ensure the campaigner's brought home as quickly as possible.
The government says Mr Bethune will have to go through the Japanese legal system - his legal team and New Zealand Embassy staff visited him in custody yesterday.
Radio Live