SYDNEY (AP) Organizers of the Bingham Cup, the world cup of gay rugby, have initiated an international study of discrimination based on sexuality in sports.

The "Out on the Fields," study was launched Friday, a day ahead of the International Day Against Homophobia and Transphobia.

Andrew Purchas, president of the Bingham Cup Sydney 2014, said the study will look at the prevalence and forms of discrimination among athletes and fans. Experts from Brunel University in London, Pennsylvania State University, University of Massachusetts, Laval University and University of Winnipeg in Canada and Victoria University in Australia will compare the data gathered across a range of countries.

The issue gained wide attention in the United States this week when Michael Sam was drafted by the St. Louis Rams, becoming the first openly gay player drafted by an NFL team.

In Australia, a player in an under-20 interstate representative rugby league match was suspended and fined for using slurs that were picked on a TV broadcast earlier this month.

"I am often asked ... about the prevalence of homophobia in sports, such as insults and abuse, particularly in very masculine team sports such as American football, or rugby," Purchas said in a statement.

"Anecdotally we know that homophobia is unfortunately very common and is the reason for people stopping playing and being involved in sport.

"However, we don't know how wide spread the problem is since there has been very little large-scale research on the issue."

Gareth Thomas, a Welsh rugby great who came out as gay in 2009, is among the high-profile athletes endorsing the study.

"Many athletes around the world fear they won't be accepted by their teammates and others if they are honest about their sexuality. I was one of those athletes and I wish, at the time, I understood how many other people were experiencing the same thing," Thomas was quoted as saying. "We need to change sporting culture."

Organizers described it as the world's first large-scale quantitative study on the issue, and were hoping for 5,000 respondents. The final report is expected to be released before the Bingham Cup tournament in August.

David Pocock, who plays for Australia's national team and is an active supporter of the anti-discrimination campaign, said gathering examples of real experiences from people was important to the study.

"Then we can begin challenging prejudice at all levels of sport, from when kids are starting out right up to professional levels," he said.