Police searched offices at Kawaguchi High School in Saitama Prefecture on March 9 after its principal was arrested the previous day on suspicion of threatening a woman who tried to break up with him, police said.

The police confiscated computers from the principal's office at the city-run school, where Principal Kazuo Ichikawa, 56, allegedly sent threatening e-mail messages to the woman, who is in her 20s.

Ichikawa began acquainting himself with the woman around January 2002, when he was assistant principal at another high school in the prefecture where she was a student, police said.

In March 2007, she proposed ending the relationship, and Ichikawa is suspected of sending more than 10 threatening electronic messages to her between late November and mid-December to prevent her from ending it, they said.