Queen's University has said it cancelled a conference about the Charlie Hebdo massacre because no risk assessment had been carried out.
The Belfast institution had been due to host a symposium in June on the fallout from the mass murder at the satirical magazine in Paris and its implications for free speech.
Twelve people were killed when Islamist extremists opened fire at the magazine's offices in January.
Academics criticised the university after receiving a letter from the organiser claiming vice chancellor Patrick Johnston had concerns over security and QUB's reputation.
Professor Max Silverman from Leeds University, who was due to speak at the event, said: "I believe universities are places of learning, are places of discussion, places of debate. If you are going to censor those sort of debates taking place then I think that's a worrying sign."
Queen's said it was a requirement for campus events to have a full risk assessment beforehand.
"Unfortunately the proposed symposium... did not have a completed risk assessment and as a result the institute has cancelled the event," it said.