Oxford University has become embroiled in a race row after students received an email from staff telling them to be “vigilant” because a black man was seen walking through college grounds.

Harris Manchester College (HMC) has been accused of “despicable” double standards for urging undergraduates to “alert a member of staff” if the man is seen again - while white students and graduates frequently “wander around college” without triggering safety alerts.

Femi Nylander, a 22-year-old prominent Rhodes Must Fall activist, had worked in a friend’s office overnight after accidentally becoming locked in HMC’s grounds on Thursday evening.