New Zealand Customs Investigations Manager Bruce Berry joins Mike Hosking to talk about Custom' investigation into the cruise ship Ruby Princess, and whether any rules were broken during the Covid-19 pandemic.

The Ruby Princess visited New Zealand and Australian ports mid-March, and allowed passengers off in Sydney when many were feeling ill.

The virus tore through the ship and sparked cases in Australia and New Zealand. Sixteen cases in Hawke's Bay have been linked back to the ship which docked in Napier on March 14.

Since disembarking in Sydney, 18 passengers from the ship have died and hundreds of confirmed cases have been linked to the vessel.

Ardern also announced that on Wednesday the Government will launch a digital diary app to aid physical contact tracing methods.

The app, developed by the Ministry of Health, would help people log their movements and allows people to keep the data to themselves, rather than share it with other businesses.

The Government is still looking at other digital contact-tracing apps, Prime Minister Ardern said yesterday.

Mr Berry says they will look at "a bit of everything", including the cruise ship company and passengers.

He adds they need to understand the context of what is going on, and offences around the advance notice of arrival declarations that are made.