HONOLULU -- A McKinley High School teacher's aide who works with special education students is accused of sexually abusing one of them.

The girl said it is the second time the man has sexually assaulted her.

The teacher's aide has been placed on leave from McKinley and in custody at Oahu Community Correctional Center charged with two counts of second-degree sexual assault and two counts of fourth-degree sexual assault.

The 17-year-old student told police she was cleaning a special education classroom at McKinley when one of her teacher's aides entered and sexually assaulted her. She said he forced her to perform oral sex on him until another male school employee came into the classroom, interrupting the assault.

"We are doing all that we can to ensure the safety of everybody on campus," Principal Peter Chun said.

Chun said the aide, Gregory Orlando Pili Keau, 38, had worked at the school for more than five years.

"He's pretty much worked as an educational assistant the whole time, and we've really never had any problems. So, this is quite a surprise to us," Chun said.

The girl told police the incident was not a surprise to her, because she said Keau sexually assaulted her in the same classroom once before, when she was 16.

Keau turned himself in to police Sunday night and was charged with sexual assault on Monday.

The Department of Education has placed him on leave while it begins an internal investigation to determine if he should be fired.

"We feel comfortable that the investigations that are going on right now are going to be appropriate and are going to take care of any concerns that any of us would have," Chun said. "We want to assure all of our parents and our students and employees that we're taking this very seriously and that we really care about their safety and well being."

Keau has two misdemeanor criminal convictions for third-degree assault in a family court case in 2003 when he was sentenced to six days behind bars, and for driving without a license in 1999, when he paid a $75 fine.