A Singaporean journalism professor and outspoken critic of restrictions on media freedom in Singapore — where Yale is establishing a joint college with the National University of Singapore — has been denied tenure at Nanyang Technological University for a second time, sparking renewed debate about freedom of thought at Singaporean universities.

George Cherian, an associate professor in journalism studies at Nanyang’s School of Communication and Information in Singapore, was first denied tenure in 2009 and then again in this month. He has been a vocal critic of Singapore’s lack of media freedom and published a book last year titled “Freedom From The Press,” in which he argues that the city-state’s media system has been structured to enable the People’s Action Party — Singapore’s leading party — to manipulate the media.

In a Tuesday evening statement, the Singaporean university said it cannot comment of specific tenure cases, adding that the tenure process at the school is “rigorous.”

But Cherian’s supporters suspect that his difficulties obtaining tenure might be due to political reasons. His case has reignited conversations about media freedom in Singapore and academic freedom in universities.

“I am aware of this case, but of course am not in a position to comment on all of the considerations taken into account in Nanyang Technological University’s decision not to award tenure,” Yale-NUS President Pericles Lewis said in a Tuesday email.

Lewis said decisions about tenure at the Singaporean liberal arts college will be based exclusively on academic merit, adding that the school’s tenure system will be “similar to other leading liberal arts colleges, with review for promotion to tenure ordinarily during the candidate’s sixth year of teaching.” Academic freedom is a “bedrock principle” of the new college, Lewis added.

Cherian’s former students have started an online petition urging the university to publicly disclose its reasons for denying Cherian tenure and to clarify the details of the school’s tenure process. As of press time, the petition had 891 signatures.