The majority of skateboarders who will take part in the 2020 Tokyo Olympics will be "weed smokers or alcoholics", a skateboarder from Sydney has warned.

Javier Coca made the comment days after skateboarding was chosen as one of the new five sports to be introduced at the 2020 Games.

"Most of these dudes are crazy, like weed smokers or alcoholics and taking party drugs. And if there's a drug test 95% of them won't be able to compete. I think it's going to be quite hard [for skaters] to get clean for the Olympics," Coca told Vice.

Same have expressed fears that introducing skateboarding at the Olympics will change the nature of the sport.

Cameron Sparkes, a member of the Sydney Skateboarding Association, said: "When I hear people talking about the Olympics, skateboarding is referred to as a 'sport.' For me, it's the polar opposite of that.

"Being included in the Olympics and that competitive nature will erode the cultural values [skateboarders] cherish more than anything."

However, other people seem to think the decision will benefit skaters.

"Skaters will profit. I know a lot of guys that do the hard lifting behind the scenes in lobbying for skate parks and skate park maintenance. These people's jobs become easier with the Olympic stamp of approval, and their work to make skateboarding better will yield more fruit – better conditions for skaters," said Renton Millar, executive board member for the International Skateboarding Federation (ISF). He was part of the team involved in getting the sport into the 2020 Olympics.

The other sports that will be introduced in the next Olympics are surfing, baseball, karate and sports climbing.