A leading children's charity said decisions about child protection and rehabilitating offenders are too complex to be left to colleges alone.
Marcus Erooga, professional advisor on child sexual abuse for the National Society for the Prevention of Cruelty to Children, said that experts from the police and probation services should take the lead in deciding whether it is safe for former offenders to study in colleges. He said the Government should set a clear procedure for colleges.
"In terms of asking for previous convictions, we would look to central government for guidance," he said. "Another issue is what they do when they receive the information. It may have no bearing on whether someone presents a risk or concern to the young people in college."
He said colleges should have a person with a designated responsibility for child protection who would build up confidence and some expertise in the area. They would then be able to liaise with the police and probation experts.
Colleges are not prevented from asking prospective adult students about previous convictions. Despite their independence from local government, some also receive advice from the local authority head of children's services on child protection matters.
In the most serious cases, the police or the courts can issue offenders with a Sexual Offences Prevention Order, which can set special restrictions on an offender, such as barring them from colleges.
Mr Erooga said colleges that ask for disclosure will face different dilemmas. "You might find out a student is a convicted bank robber," he said. "And having got that information, you have to find ways of keeping it confidential."