Australians will be able to dob on sick neighbours and large crowds at sport matches could be banned as the Morrison government activates sweeping powers that will give it the power to forcibly detain people in fever clinics.

In an escalation of the government's response to the coronavirus outbreak that has killed more than 3000 and infected 90,309, Attorney-General Christian Porter said the "strange and foreign" powers under the Biosecurity Act were designed "precisely with the type of pandemic in mind that we are now facing".

The Morrison government is again expected to extend its travel ban on all non-residents travelling from China and Iran when the national security committee meets on Thursday and is now seriously considering further measures on South Korea and Italy, which have more than 6000 cases between them.

The threat of local transmissions has escalated in recent days as the number of cases in NSW jumped from four to 13 in the space of a week after two females in their 60s returned to Sydney from South Korea and Japan. Nine have been confirmed in Victoria.