Prime Minister John Key flatly denies New Zealand is about to sign a deal with Australia to resettle refugees detained on Manus Island and Nauru. Speculation about such a deal has been prompted by the Australian Prime Minister Malcolm Turnbull's announcement that asylum-seekers who arrive by boat will be prevented by law from ever being let into the country. The denial comes as a United Nations investigator arrives in Australia today for an 18-day visit to immigration detention centres. The proposed Australian law would cover asylum-seekers on Manus Island and Nauru. New Zealand has offered to take 150 people from Nauru a year but Mr Key said while the offer remained on the table, Australia showed no inclination to take it up. However, a source told the ABC the only way the proposed new law…