Further doubts have been cast over the staging of the opening Grand Slam of the year after a 26-year-old man, who was working at the Grand Hyatt Hotel where hundreds of players were staying, tested positive for COVID-19.

As a result, more than 500 players, officials and support staff who were deemed to be close contacts have been forced to self-isolate until they produce a negative test result.

All of today’s matches across six warm-up events at Melbourne Park have been postponed and the main draw, which was scheduled to be held this morning, has been pushed back by 24 hours.

But Tiley - who has previously rejected calls for the Australian Open to be delayed due to player dismay over strict quarantine rules - remains adamant the tournament will start on Monday (February 8) as scheduled.

"We’re absolutely confident the Australian Open will go ahead," said Tiley, who is also chief executive of Tennis Australia.

"We will be starting on Monday and we have no intention of changing times."

Tiley confirmed 507 players and staff had been affected by the positive case but expected them all to be released from isolation with tests due to be held later today.

"We know that we have a period now where we have to work with those 507 players and their staff," said Tiley.

"The probability is very low that there’ll be an issue though.

"We expect them all to test negative.

"The plan is to continue to play [in the lead-up events] 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 as scheduled."

Three Women’s Tennis Association (WTA) tournaments and three Association Tennis Professionals (ATP) events are due to be concluded this weekend.

Tiley said Tennis Australia would hold talks with the ATP and WTA over the possibility of making adjustments to ensure the competitions finish on time.

"With the lead-in events, there’s many options that we could have," said Tiley.

"We could look at formats on scores, we could look at the number of courts we’re using. 

"We’ll work closely with the WTA and the ATP to figure out what’s the most optimal schedule for that.

"We’re doing that in the next five or six hours."

Victoria Premier Daniel Andrews said there were "no need for people to panic" following the positive case but was unable to give any certainty over whether Australian Open could be disrupted.

"We all understand that there’s no guarantees in any of this," said Andrews.

"But at this stage, the tournament shouldn’t be impacted by this.

"These things can change."

COVID-19 has dominated the build-up to the event, with 72 players unable to leave their hotel rooms for two weeks after flying in on planes where positives cases were later detected.

These players completed their spells of quarantine - which proved highly contentious - last week, while others had been allowed to leave their rooms for five hours a day to train.

It was previously announced that up to 30,000 spectators will be permitted to attend the opening eight days of the Australian Open, with this number falling to 25,000 per day from the quarter-final stage.

At least 10 people tested positive for COVID-19 while in the quarantine hotels, including three who contracted the more virulent United Kingdom strain.