Larry Hirst took his third leave of absense in the past four seasons, but this time he said he won’t come back to coach at Newport Harbor. (KEVIN CHANG, Daily Pilot / January 7, 2012)

Newport Harbor High School Principal Michael Vossen has suspended the boys' basketball program indefinitely because of "criminal threats" directed toward Coach Larry Hirst and his wife, Sheridan, Vossen said in an email sent to parents of the players Wednesday night.

The Newport Beach and Huntington Beach Police Departments are investigating the matter, the email said. Possible suspects include individuals associated with the Newport Harbor boys' basketball program, Vossen said in the email.

Hirst has stepped down as coach, saying that it was his time to go.

"The vast majority of our parents and students understand the lines of civility; clearly the lines of civility were lost in this instance," Vossen said Friday night. "I'm just extremely upset that we lost a really good coach as a result of this."

Hirst and his wife are both teachers at Newport Harbor. Because of the investigation, Larry Hirst declined to detail the threats, only saying that it was a threat of physical harm toward him and his family. The threats were occurring at Hirst's home and at Newport Harbor, Vossen said Friday night.

"Individuals found responsible for these acts will be prosecuted to the fullest extent possible under the criminal code and may also be subject to additional disciplinary consequences under District/school policy," Vossen said in the email.

Larry Hirst took a personal leave of absence from the team in January amid a 10-game losing streak. Two months later, he returned as coach after the season ended. The Sailors went 7-17 and 2-8 in the Sunset League.

Larry Hirst has taken a leave of absence as coach three times in the past four seasons, but this time he said he won't come back to coach at Newport Harbor.

"Lots of friends have already asked me to [coach]," he said. "I think I'm going to lay low for a while until the perfect, and I mean perfect, situation steps up."

steve.virgen@latimes.com

Twitter: @SteveVirgen