A state politician who was giving a lecture to high school students inserted a data memory stick into a computer and the projected image of nude woman appeared on a screen, the state highway patrol said.

The memory stick, along with a school computer used Tuesday by state Rep. Matthew Barrett, were taken into custody and were being examined, said patrol spokesman Lt. Tony Bradshaw.

Investigators interviewed Barrett and various school officials to determine if the image of the woman came from the memory stick or the school computer, Bradshaw said.

Barrett, who was giving a civics presentation to about 20 students in a senior government class at Norwalk High School in northern Ohio, said school's technology director looked at the memory stick and determined that it had a directory of nude images.

"I have no idea where these came from," said Barrett, a Democrat from Amherst in northeast Ohio.

Barrett said there were a few snickers from students when the image of a topless woman appeared on the screen. He then immediately pulled the memory stick out of the computer.

He said he rarely used the stick, which was a gift he received about three weeks ago from a legislative liaison from the state Library of Ohio. It was not piece of state property, Barrett said.

The stick contained a graphics presentation — downloaded earlier by Barrett — on how a bill becomes a law and other civics lessons, he said. He finished his lecture using printouts and then met with the school's principal and technology staff, who examined the stick. They all agreed to call police, Barrett said.

Barrett said he's eager to find out where the images came from, and he voluntarily turned over to investigators a personal laptop the he also brought to the school.