More than half the pupils in Colwyn Bay assessed for educational special needs in the last academic year had moved into the area in the last two years, according to the confidential report.

Teachers are under great strain

One former headteacher said he quit his post because of the problem.

He told Taro Naw that up to 130 incomers - many with complex problems - would arrive each year and in the same year about 120 would leave.

The programme's findings are likely to further fuel the row over incomers to Wales.

Taro Naw found that Conwy's education department has dealt with 35 children who moved into the county in the last 12 months with an LEA statement declaring they had special educational needs.

This has cost the authority �160,000.

It was also discovered that about the same number of pupils move into the area without statements each year, yet they also require special education.

These children are put in the same classes as other pupils until it is realised they need extra help.

There was a transient population of 25% in the school

Brian Morris, former headteacher

It is claimed that this not only disrupts education for both sets of pupils but also takes weeks for the local authority to make the assessment, once a teacher realises the child needs special lessons.

The cost of making the assessment and providing the education then falls on the local authority.

The situation has become so bad that one North Wales headmaster has quit his job partly because of the strain.

'Transient pupils'

Brian Morris, previously head of Christchurch School, Rhyl, quit his job last year partly because of the problems.

He claims the influx of families with social problems moving into the area is putting a strain on education and teaching staff.

"There was a transient population of 25% in the school," he said. "Every year around 130 incomers would arrive - and in the same year about 120 would leave.

"The children came from Birmingham, Manchester, Liverpool and Warrington - a lot of them with complex problems; a lot coming from broken homes.

"Some of the incomers had drug problems and others had a suspicious interest in children."

Headteachers in the area claim resources are being hit and teachers are leaving because of the problem.