POLICE have been called into St John's College at the University of Sydney and a hotel ''safe house'' organised amid fears for the safety of several students who have spoken out against ritual abuse and widespread destruction on campus.

After a week-long ''witch-hunt'' by senior students, police have been drafted to investigate violent threats against so-called ''moles'' and whistleblowers who have been exposing the college's mob rule culture from within.

Under investigation ... St John's College at the University of Sydney. Credit:Janie Barrett

An honorary professor at the university, Roslyn Arnold, revealed she had advised the college's rector, Michael Bongers, to ''put those at risk in alternative accommodation as soon as possible''.

Professor Arnold, who quit the St John's executive this semester, said: ''There is a witch-hunt taking place to trace all those students who have been brave enough to speak out against the ongoing humiliation and abuse.