The world's largest e-sports organization has said it will crack down on the use of drugs intended to give players an edge in video game tournaments.

The move by Germany-based Electronic Sports League came after a professional player went on the record in an online interview saying he and a group of former teammates "were all on Adderall" during a Counter-Strike: Global Offensive game match.

Adderall is an amphetamine that stimulates neurotransmitters in the brain and is commonly used to treat attention deficit disorders.

"The popularity and visibility of e-sports has grown exponentially in recent years, but this combined with the increasing size of prize pools has also made the temptation of rule-breaking even greater," ESL said in post online at eslgaming.com announcing a crackdown on doping.

"We will taking immediate action to ensure that ESL's company values of exemplary sportsmanship and integrity are maintained."

Skin testing will be done at an ESL One Cologne tournament in August to check whether players are using performance enhancing drugs, according to the post.

ESL, which bills itself as the oldest and largest e-sports organization, is looking to make such testing standard practice after an official policy is established and tournament rules are updated.

"We wish to ensure we can provide a fair playing field for all participating players," the organization said.

An e-sports trend of video games drawing huge audiences as spectator sports has boomed in recent years, bringing with it big cash prizes at tournaments; teams with deep-pocketed sponsors, and even wagering on outcomes.

Start-up Unikrn recently announced a fresh round of funding that valued the e-sports wagering company at $40 million.

Unikrn launched its e-sports betting arena in Australia about two months ago in a partnership with Tabcorp, a wagering specialty firm with global reach.

The startup expanded to Britain and Ireland in May, accepting bets on the outcomes of team combat in "League of Legends," "Dota 2" and "Counter-Strike: Global Offensive."

Unikrn co-founder Rahul Sood in June told AFP that he hoped to crack the US market, where betting on e-sports remains illegal.

More than 21 million people tuned into Twitch broadcasts from the Electronic Entertainment Expo (E3) video game industry extravaganza that took place mid-June in Los Angeles, according to the Amazon-owned company.

YouTube is wading confidently into turf dominated by Twitch, with the pending roll-out in Britain and the United States of a service tailored for the hot trend of video game play as a spectator sport.

YouTube Gaming was designed as an online arena for video game channels incorporating the search smarts of Google, which owns YouTube, to surface fresh or must-see content.

Billions of hours of video related to gaming are watched monthly at YouTube, from "walk-through" clips showing players how to handle challenges, to comedic commentary and in-game action.