Harvard University's Team Ambush have been disqualified from the Heroes of the Dorm tournament, an eSports competition for colleges in the US, for adding an ineligible player to the team's roster, 24 March. An investigation by Blizzard Entertainment and Tespa found that a player on the team was sharing his Battle.net account with a higher-ranked player who was not on the Harvard team's submitted roster.

"We have zero tolerance for cheating in our tournaments," Blizzard Entertainment said in a statement. "The rules are in place to ensure a fair playing field for all participants – when these rules are abused they put the integrity of the competition at risk. The students found to be sharing their Battle.net accounts and the players with whom they were sharing will be banned indefinitely from participation in any future Tespa tournaments."

Team Ambush, which made it to round 16 in the competitive gaming tournament, issued an apology saying that a team member and the team's substitute were not able to participate after the qualifiers due to a lack of internet access.

"During this period of time, we were uncertain about how to continue, since we really wanted to continue participating in this event and did not want to forfeit by not having enough players for the first weekend in bracket play, which we worked hard to achieve," the team wrote in a Medium post.

They defeated a team from the University of Berkeley in the first round of the tournament and Indiana-Purdue in round 32 with the illegal substitute. "As individuals who should have been fully aware not only of the rules of the tournament but also of the moral implications of our actions and their effects on others, we recognize that we have committed a grave error and can only ask for forgiveness," the team said.

The team from UC Berkeley, last year's Dorm champs, were allowed to take Harvard's vacated spot in the Super Sixteen round of 64-team, bracket-style tournament. Michigan's Team Hot Boys was also disqualified in round 64 for sharing accounts as well.

"While Harvard College does not comment on individual students, we consider honesty a foundational value for Harvard in the classroom, in student housing, and in extracurricular activities," Harvard College spokeswoman Rachael Dane said in a statement to Motherboard.

UCONN, UTA, Tennessee, and ASU have all moved on to the #HeroesoftheDorm Heroic Four! Watch them battle it out live at the CenturyLink Field Event Center in Seattle April 9 & 10! RSVP > http://blizz.ly/DormEvent Posted by Heroes of the Storm on Sunday, March 27, 2016

Collegiate teams in the competitive eSports tournament, play Blizzard Entertainment's online action game, Heroes Of The Storm, with players using Battle.net accounts to log in and compete with characters in an arena.

Each player in the winning team will win an annual scholarship of up to $25,000 for a maximum of three years. Each member of a "Heroic Four" team will receive a gaming PC built by Cyberpower.

Competitive gaming popularity has mushroomed in recent years with games like League Of Legends, Counter Strike and Dota 2 evolving from leisurely hobbies to arena-filling, seven-figure prize-winning events.

Last week, Electronic Arts (EA) hosted the Fifa Interactive World Cup Grand Final in New York City where 32 players competed on PlayStation 4 and Xbox One for $20,000 (about £17,500) and a trip to the next Fifa Ballon d'Or in Zurich. More than two million players from around the world took part in the online qualification round for the largest video gaming tournament in the world.

According to SuperData, the quickly rising eSports market is valued at $747m and is expected to more than double to $1.9bn by 2018. Having garnered an estimated audience of 134 million in 2015, more video game publishers, developers and media networks are looking to cash in on the digital action.

While video game publishers including EA, Microsoft, Psyonix and Activision have taken to hosting their own tournaments, media companies including ESPN and Yahoo have launched their own verticals exclusively dedicated to competitive video-gaming coverage.

"There's a generation of sports fans growing with eSports as their primary sport of choice," Whalen Rozelle, director of eSports at Riot Games, told 12News. "They're not dipping in and watching basketball, hockey or football. This is a generation that really focused in on this as their sport."