NORWALK - An art teacher at Brien McMahon High School in Norwalk pleaded not guilty yesterday to charges he carried on a sexual relationship with a 17-year-old student.

Police say they received a tip last month that John Tate was having an affair with the girl.

According to the search warrant, the teen claims to have had sex with Tate about 20 times, including several times in a classroom and once in a cemetery. Police say there are suggestive e-mails in which Tate uses the alias "Tom Wright."

The warrant also says Tate and the teen discussed marriage and use of emergency contraception.

Tate's lawyer says he is on leave from Brien McMahon and is free after posting $150,000 bond.

Norwalk teacher charged with sexual assault