OLYMPIA, Wash. - While Washington's four teams in the Western Hockey League are under investigation for child labour practices, the state Legislature is considering a league request to exempt amateur athletes from state labour laws.

In a hearing before the Washington state Senate's Commerce and Labor Committee Wednesday, officials from the state's WHL teams and the league office said the Seattle Thunderbirds, Spokane Chiefs, Tri-City Americans and Everett Silvertips might have to leave or shut down if state law isn't changed to consider amateur athletes non-employees.

The state's Labor and Industry department has been investigating all four teams since a complaint was filed in 2013 over working conditions for their players, who range in age from 16 to 20 years old and play a 72-game regular season. If the players are considered employees, they are subject to state laws governing minimum wage and working conditions, including child labour laws.

"If the bill is not passed, it could negatively impact our ability to operate and would force us to move or not operate in the state," Silvertips general manager Garry Davidson told the Senate committee.

The 22-team league, along with two others, operates at the highest level of Canadian junior hockey and feeds players to National Hockey League teams. Its athletes are paid stipends, live with host families and earn a year of college scholarship for each season they compete in the league. The only U.S. team in the WHL outside of Washington is the Portland Winterhawks. Oregon officials looked into a child labour complaint against that team last year but did not launch a formal investigation, a spokesman for the state's labour department said.

In Washington, the league and teams face possible civil penalties and other consequences if the Labor and Industry department finds violations. The department consulted with state Attorney General Bob Ferguson's office in December on the investigation and is currently seeking more information from each team, Labor and Industry spokesman Matthew Erlich said.

Several class-action lawsuits are pending in Canada over pay for junior-league hockey players. The lawyer behind them, Theodore Charney of Toronto, said weather prevented him from attending Wednesday's hearing but sent a six-page letter criticizing the bill for its attempt to deny players coverage under Washington's minimum-wage and labour conditions laws. Charney said in a telephone interview that no other U.S. state or Canadian province has attempted similar legislation and that he doesn't consider the hockey players' position similar to that of college athletes.

"The hockey teams are not universities, they're for-profit businesses," Charney said.

The Senate bill passed a committee vote unopposed Wednesday evening. A companion bill comes before the House Committee on Labor for a vote Thursday morning.

"We certainly don't want to lose amateur hockey in this state," Senate Commerce and Labor committee chairman Michael Baumgartner, R-Spokane, said.