The message for people who left MIQ in Auckland's Pullman Hotel, to isolate again ... has gone international

Australia's extended its suspension of quarantine-free travel from New Zealand another 72 hours -- now lapsing on Sunday, at 4pm.

It was introduced on Monday after confirmation our Northland case had the South African Covid-19 strain.

Acting chief medical officer Michael Kidd says a number of returnees at the Pullman at the same time crossed the Tasman.

He says everyone is being followed up by authorities in the state they landed.

Kidd says they know 12 arrived in Sydney -- with three then travelling to Hong Kong, and two travelling to Queensland.