A Washington state high school teacher is under fire after flashing topless photos to stunned students during a classroom presentation, according to the principal.

The unidentified teacher at Glacier Peak High School in Snohomish exposed four explicit images of a woman’s bare breasts while giving a PowerPoint presentation to students on Wednesday — a disturbing blunder that principal Alicia Mitchell branded an accident in a letter sent home to parents.

“We want to make you aware of an incident in a classroom where inappropriate images were inadvertently shared with the students,” Mitchell said in the letter obtained by The Post.

“It is our understanding that these images have since been viewed by many others beyond the classroom and want to give you an opportunity to process with your student if you choose to do so. The content included images of nude breasts and were briefly visible during a teacher’s PowerPoint presentation.”

She said the troubling mistake, which is under investigation, is not a reflection of the school’s “expectations for classroom materials.”

Mitchell did not name the teacher or offer further details.

Seattle Red radio host Jason Rantz said he was sent the shocking presentation, which allegedly featured the four images of exposed bosoms displayed in small preview-style boxes on one of the slides.

He said the layout made the pics appear like “previews of photos from a folder.”

It’s unclear if the photos were of the teacher or another individual. It’s also unknown if the educator has been suspended amid the probe.

“As this is a personnel matter currently under investigation, we’re unable to provide additional details or comment further,” a school spokesperson told The Post in a statement.

“We take this matter seriously and are following established processes to review the situation and determine next steps.”