Australian Open chief Craig Tiley said he was "absolutely confident" the tournament will start next week despite a fresh coronavirus case that halted warm-up tournaments and forced hundreds of players and officials into isolation on Thursday.

The case, a worker at one of the Melbourne tournament's designated quarantine hotels, has caused yet more chaos before the year's first tennis Grand Slam, which has already been delayed three weeks over coronavirus problems. But Tiley said the Open would start as scheduled on Monday, and that there were no plans to cancel. Play was suspended at six warm-up tournaments in Melbourne on Thursday.

"We're absolutely confident the Australian Open will go ahead," Tiley told reporters. "The plan is to continue to play tomorrow as planned. If we have to go through this again, we'll go through this again.

"We have three and a half weeks of tennis to play and we'll go in as scheduled."

The incident highlights the difficulty of holding large-scale, international sports events during the pandemic, as officials wrestle over how to safely hold this year's Tokyo Olympics.  

Health officials insisted the risk to players and officials, who queued up for coronavirus tests on Thursday, was "low."

Victoria state Health Minister Martin Foley said the 520 people ordered to isolate and get tested were casual contacts, stressing "we are not as concerned about them."

"But out of an abundance of caution we want to ensure we leave no stone unturned in how we follow up and deal with anybody who may have had contact with this ­individual," he said.

Dedicated facilities were set up to ensure they all get tested quickly, with results often returned within 24 hours.

The Australian Open draw, which was scheduled to take place on Thursday, has been pushed back by a day.