A university "confessions" page has been reported to police after coded racist messages were posted.
ExeHonestly, which allows students to post anonymously via Facebook, hosted references to Adolf Hitler and white supremacy.
Admins for the unofficial Exeter University page said the messages had "slipped" past its moderators.
The university said the posts raised "deep concerns" and it was working with police to "identify those responsible".
It acted after the alarm was raised by students on Twitter, according to student newspaper The Tab Exeter.
Police were contacted about two posts on the page, which have since been deleted.
One included the number 88 - said to be code for "Heil Hitler", while another promised users "a bag of sweeties" if they could solve a riddle.
The question: "What accounts for 15%, yet 32%?" references a disputed statistic relating to the number of crimes committed by African Americans.
The university said it had reported the posts to Facebook and Devon and Cornwall Police's hate crime unit.
It would take "immediate action" against any students posting abusive content, it said in a statement.
"Racism cannot be tolerated in any form in our community," it said.
Administrators for the page, which is followed by more than 14,500 people, said the "true meaning" of the "dog-whistle" posts was "not apparent to people unless they have specialised knowledge".
They said the page received "hundreds of confessions a day" which are "moderated by a handful of students with degrees and lives".
"As a result, distasteful posts may slip through moderation," they said.
Tab editor Emily-Jane Heap said it was a "shame" that a "minority of people" had posted the abusive posts on the Facebook page.