Paul Holmes, a member of parliament's education committee, this week told FE Focus he would be calling for tighter controls to prevent colleges becoming a soft target for offenders.
While there is no suggestion that Nigel Oldfield had any untoward intentions at Doncaster, Mr Holmes said this might not be the situation in other cases.
"We all know case histories of people with child sexual offences where they deliberately go into positions in which they can get access to young people," Mr Holmes said.
"It does depend what someone has been convicted for. But it would make sense for all colleges to ask for a self-declaration at the outset and to have some sort of internal body make the decision. There's certainly a loophole."
Colleges have been self-governing since 1993 when they were taken took out of local education authority control. Bill Rammell, the further and higher education minister, argues that this means they must take responsibility themselves for safeguarding students. But further guidance is being developed, he said. "All colleges are self-governing institutions and should contact the authorities if they suspect a student or member of staff has committed an offence.
"We have made changes to ensure that all students in FE whose studies bring them into regular contact with children should be assessed for their suitability, and this will include a CRB check.
"This is on top of regulations requiring all those providing education in FE colleges to undergo checks, and colleges must hold a central record of these checks.