QUEENS - An English teacher at Richmond High School in Queens was arrested Thursday after city investigators say she raped a male student.

Investigators say Janmatti Singh, 22, had sex with the 18-year-old student in January. They say the alleged crime happened in Brooklyn.

They also allege that Singh met with the students? cousins, who are 18 and 15, and also had sex with them.

Students at Richmond High School were surprised by the news.

?It?s crazy because she was a real beautiful teacher,? says Timothy Johnson, who attends Richmond.

A lawyer for Singh says she suffers from bipolar disorder and was taken advantage of by the boys.

Singh has pleaded not guilty to charges of rape, sexual misconduct and endangering the welfare of a child.

The Department of Education says Singh had actually been on medical leave since November 2007.