PUPILS in the region are "seriously jeopardising" the careers of their teachers by creating pornographic images of them and putting them on the Internet, a union has warned.

In a prank which is proving increasingly popular, children are downloading pornography from the Internet or scanning in pictures from magazines and pasting on their teachers' faces.

Some then e-mail the pictures to their friends or put the images back on the Internet, said the National Association of Schoolmasters' Union of Women Teachers.

In one case at a Northern school, an image was seen by hundreds of pupils when a youngster downloaded pornography on his home computer and scanned a woman teacher's face on to the picture.

He then sent it to all his friends by e-mail.

Hans Ruyssenaars, the union's national executive member for Cleveland, said: "We have a situation here where teachers, without any culpability on their part whatsoever, are being flaunted around the Internet without their knowledge.

"Their careers could be very seriously jeopardised as a result.

"From the kids' point of view, it's just a silly game to play. They don't realise the amount of damage that they're doing, but clearly our members are being exposed to extreme risk in this way.

"If it becomes public knowledge, the reputation of the teacher is tarnished and they will have great difficulty facing pupils in the classroom knowing their pictures are going around.

"They will feel sullied and dirty as a result of it."

He said a number of cases had cropped up across the country, including in the North-East.

He added that parents should be forced to take responsibility for their children's actions if they were caught.

He said: "A number of parents are all too happy to abandon their children to videos, computer games or the Internet, without any idea as to what they are up to.

"In our view, it is time for parents to take a much greater interest in what their children are doing."