Sydney  – This month’s swimming grand prix in Melbourne has been cancelled because of fears that competitors could infect each other with swine flu.

Most of Australia’s H1N1 cases are in Melbourne and the difficulty of arranging quarantine has put paid to the June 20-21 event, Swimming Australia announced Tuesday.

“Swimming Australia has a duty of care in relation to our athletes, as well as ensuring we give them be the best chance possible to prepare for the world championships (next month) in Rome,” chief executive Kevin Neil said.

“It’s a regrettable decision to have to make, yet one that we have made with all the information available.”

He also said that swimmers and support staff travelling overseas in the lead up to Rome would be screened by team medical staff on their return.

Meanwhile, National Rugby League (NRL) chief executive David Gallop warned of upheaval this season if matches had to be cancelled because players had to be quarantined.

“It’s a concern, but as I said we can only take advice from the public health authorities and that’s what we’re doing,” Gallop said.

Star NRL players were forced into quarantine following a game in flu-hit Melbourne. The Queensland squad that played in last week’s encounter with the New South Wales team were asked to stay at home for 72 hours to try and prevent the bug being passed on.

After the New South Wales team physiotherapist also tested positive to the H1N1 virus, that state’s squad was put into quarantine as well.

There have been over 1,000 swine-flu cases reported in Melbourne, with some media outlets dubbing it the swine flu capital of the world because it has the highest per capita rate of infections. (dpa)