A Spanish tennis player who was among many Australian Open competitors to complain about quarantine rules has revealed she has coronavirus.

Paula Badosa said she had felt unwell with symptoms before testing positive for the virus in Melbourne on Thursday.

Badosa is believed to be the fourth competitor to test positive in hotel quarantine, but is the first to identify herself publicly.

On Friday, she said "sorry guys", adding quarantine rules were "pivotal".

The 23-year-old said she had been taken to a separate hotel in Melbourne to "self-isolate and be monitored".

Melbourne endured one of the world's longest lockdowns last year and many locals have concerns about the potential Covid19 risk posed by the tournament.

Badosa is one of 72 players who have been confined full-time to their hotel rooms for 14 days - under a state health order - after the infections were discovered. She has already spent seven days in isolation.

Players who arrived on flights with no infections are also in quarantine but are allowed five hours of court practice a day.