Marshall reveals he has tested positive to COVID-19

He told 2GB's Ben Fordham this morning he is asymptomatic and has been in full isolation since Tuesday night.

He went to a pizza restaurant in Paddington on Monday night with three other Nats including the member for Cootamundra Steph Cooke. All four went straight into isolation. A positive case had attended the pizza restuarant, Christos, at the same time.

Mr Marshall issued this statement at 8.45 this morning telling everyone to "take care".

"This morning just after 8am I was formally advised by NSW Health that I had returned a positive test for COVID-19," he said.

"I have been in isolation in Sydney since late Tuesday night, when I received a text message from NSW Health advising of my attendance at a close contact venue on Monday evening, and the need to present for testing.

"To everyone who has contacted me this morning, thank you for your thoughts and well wishes - I'm doing fine and will continue to strictly follow the advice of health authorities.

"To our wonderful NSW Health staff, who continue to do an amazing job in these challenging times, thank you for your support and efforts keeping all of us safe and well.

"Take care everyone."

Health Minister Brad Hazzard has been forced to go into isolation as well after having been deemed a close contact. An infected person was in state parliament and the NSW Labor's budget in reply speech may be delayed - or even parliament.

"When I woke up this morning about 5.30 there was a text message from NSW Health advising me that there is a possible positive case who works at Parliament House in Sydney and that I should therefore self-isolate until further notice," Mr Hazzard told Sunrise on Channel Seven.

Mr Marshall has been in Sydney for parliament this week and the budget. On Wednesday morning, NSW Health confirmed 10 cases of coronavirus had been confirmed in the 24 hours to 8pm on Tuesday.

Health authorities also confirmed 13 additional positive cases of the virus had been detected since the Tuesday night cut off.

Many believe Sydney is headed for a lockdown as cases grow and seven local government areas have been declared a hotspot. People in those areas are not allowed to leave the Great Sydney area.

More to come.