The NBA has banned Toronto two-way player Jontay Porter after a league investigation concluded that he disclosed confidential information to sports bettors and wagered on games.

The league said in a statement on Wednesday that an investigation found that Porter disclosed confidential information about his own health status to an individual he knew to be an NBA bettor ahead of a 20 March game against the Sacramento Kings. Another individual Porter also knew to be an NBA bettor then placed an $80,000 parlay proposition bet with an online sports book to win $1.1m, wagering that Porter would underperform in the game, the league said.

Related: ‘It’s an addiction’: NBA’s ties to gambling trouble players past and present

Porter played just three minutes against Sacramento, claiming that he felt ill. The unusual betting activity and actions of the player prompted the bet to be frozen and not paid out.

The suspicious bets in the 20 March game were brought to the NBA’s attention by licensed sports betting operators and an organization that monitors legal betting markets.

The NBA also said that Porter, who is the brother of Denver Nuggets forward Michael Porter Jr, placed at least 13 bets on NBA games from January through March while traveling with the Raptors or their G League affiliate. These bets ranged in size from $15 to $22,000 for a total of$54,904. The total payout from these bets was $76,059, resulting in net winnings of $21,965. None of the bets involved any games in which Porter played.

According to the league, three of the bets were multi-game parlay wagers that included one Raptors game, in which he bet Toronto would lose.

“There is nothing more important than protecting the integrity of NBA competition for our fans, our teams and everyone associated with our sport, which is why Jontay Porter’s blatant violations of our gaming rules are being met with the most severe punishment,” NBA commissioner Adam Silver said.

He added: “While legal sports betting creates transparency that helps identify suspicious or abnormal activity, this matter also raises important issues about the sufficiency of the regulatory framework currently in place, including the types of bets offered on our games and players. Working closely with all relevant stakeholders across the industry, we will continue to work diligently to safeguard our league and game.”

The league has partnerships and other relationships with more than two dozen gaming companies, many of whom advertise during NBA games across all platforms.

“You don’t want this for the kid, you don’t want this for our team and we don’t want this for our league, that’s for sure,” Raptors team president Masai Ujiri said Wednesday in Toronto. “My first reaction is obviously surprise, because none of us, I don’t think anybody, saw this coming.”

Porter was found to have done was in violation of the collective bargaining agreement between the NBA and its players’ union, which states: “Any Player who, directly or indirectly, wagers money or anything of value on any game or event in the Association or in the NBA G League shall, on being charged with such wagering, be given an opportunity to answer such charges after due notice, and the decision of the Commissioner shall be final, binding, and conclusive and unappealable.”

Porter averaged 4.4 points, 3.2 rebounds and 2.3 assists in 26 games, including five starts. He also played in 11 games for Memphis in the 2020-21 season.

The Raptors finished with a 25-57 record and third from bottom of the Eastern Conference, 11 games adrift of the final play-in tournament spot.