About 40 Australians due to leave India on the first repatriation flight in two weeks have tested positive to COVID-19.

Close contacts of people who tested positive will also be unable to fly, which means a total of 70 people can no longer fly home.

There were 150 Australians booked on the flight from New Delhi.

Meanwhile, a plane carrying medical supplies has left Darwin bound for the subcontinent.

Another 4,000 people have died from COVID-19 in India over the past 24 hours.