The Ministry of Health has said tonight all direct flights from Western Australia to New Zealand should be immediately paused after a worker at a Perth managed isolation facility tested positive for Covid-19.

A MOH release tonight just after 10pm tonight announcing officials had "conducted a rapid public health assessment for New Zealand" and decided the flights from Western Australia to New Zealand should be paused while further health assessments are carried out.

The call comes after a security guard working in hotel quarantine in Perth has tested positive today to Covid-19, with two of seven people sharing the man's house also returning positive results.

"Ministry officials have conducted a rapid public health assessment for New Zealand, and have determined scheduled direct flights from Western Australia to New Zealand should be immediately paused while a further assessment is carried out, including a further assessment and information from Australian health officials," the MOH statement said.

Western Australian health officials have determined a number of locations of interest listed on their website.

Anyone who has left Perth in the past four days and arrived in New Zealand should check these locations of interest.

Recent arrivals in New Zealand who have been at these locations of interest should self-isolate immediately and call Healthline in the morning for further advice.

More information will be released tomorrow, MOH said.

Western Australia Premier Mark McGowan said in a press conference on Saturday the state will not go into lockdown "at this point".

"But it's possible this could change by tomorrow or the day after," he said.

The security guard, a man in his twenties who lives in Nollamara, had already had his first dose of the coronavirus vaccine, McGowan said.

He had worked in the Pan Pacific Hotel on April 24, 25 and 26, during which time new arrivals were admitted to the hotel.

He worked on the same floor as two hotel quarantine residents who had tested positive to Covid-19.

"CCTV vision is being reviewed, however there is no clear explanation at this point as to how the security guard could have been infected," McGowan said.

"It is possible transmission could have occurred while the international arrivals were admitted into hotel quarantine and possibly were transferred to their rooms.

"This is being investigated further."

The man's household included two guests from Canberra, McGowan said.

He said the man visited several locations in the community while likely to have been infectious, including a Northlands shopping centre, a Coles, a cafe and a mosque.

The full list of locations will be uploaded to the WA government website.

They currently include:

- Masjid Al Taqwa mosque at Mirrabooka on April 30 between 1.15pm and 2pm
- Coles at Prime West Northlands Shopping Centre at Balcutta on April 29 between 4.30pm and 5.15pm
- Agha Juice cafe at Joondanna on April 28 between 6.50pm and 8pm
- Smokemart in Prime West Northlands Shopping Centre at Balcutta on April 28 between 1.30pm and 3.15pm
- Northlands Fresh at Prime West Northlands Shopping Centre at Balcutta on April 28 between 1.30pm and 3.15pm
- Spudshed at Stirling on April 28 between 1.30am and 2.30am
- Swan Taxi Victoria Park on April 27 between 1.50pm and 2.45pm