A STRING of individuals banned from teaching because of a record of child sex offences have won exemptions allowing them to work in particular schools, it emerged.

Three men placed on the confidential List 99, which is intended to bar sex offenders for life from working in schools, were cleared to take posts where it was felt they would not be tempted, The Times reported.

The revelation will increase pressure on Education Secretary Ruth Kelly, who launched a review of the vetting system after it emerged that Paul Reeve was cleared by a minister to work as a PE teacher despite a caution for viewing child pornography.

The Times highlighted cases today in which people placed on List 99 have appealed to the Care Standards Tribunal, set up in 1999 to hear cases involving work with children.

In one case, a man convicted of possessing indecent images of young boys was cleared in 2001 by then Education Secretary Estelle Morris to work in all-girl schools.

The new cases follow the news last night that a man convicted of indecent assault on a child in 1980 had since taught in two schools on Tyneside and another in County Durham.

A spokesman for the Department for Education said last night: "There is a responsibility on all employers schools and supply agencies - to carry out the necessary checks for permanent and supply teachers.

"These checks will reveal whether someone has a conviction, past or present."