Harare – Students have reportedly given the vice chancellor of the University of Zimbabwe (UZ), Levi Nyagura, 48 hours to step down from the institution over former first lady Grace Mugabe's alleged "fake" degree.In a letter delivered to UZ on Wednesday, the Zimbabwe National students' Union (Zinasu), threatened "intensified protests" to force Nyagura to step down if their call was not heeded."It is our considered view that your continued stay at the helm of the institution further degrades its already tainted image in the academic field. This is because you presided over the awarding of a bogus doctorate to Grace Mugabe," read part of the letter. This came a few weeks after academics at the UZ petitioned the country's anti-corruption commission to investigate the "suspicious" way in which Grace was awarded a PhD in orphanages four years ago.The academics from the university's sociology department said they were "shocked" when Grace emerged among the doctoral candidates in 2014. Grace was capped by her husband "This was a shock to many members of the department as most members never (saw) or heard about the proposal, progress reports, thesis examiners and outcome of such a study by the candidate," reads part of the petition, quoted by the private Zimbabwe Independent.Grace was capped by her husband, then president Robert Mugabe, in August 2014 when he was still chancellor of the university. She appeared in the red academic gown and black cap for the doctorate of philosophy degree beside the then vice president, Joice Mujuru, who also received a doctorate.Mujuru's doctoral thesis has subsequently been released into the public domain, but Grace's thesis has never been made available.At the time Grace was reported to have enrolled for the doctorate just three months before it was awarded. Prominent graduates of the university, which has a distinguished track record, were outraged. The late Zimbabwean author, Chenjerai Hove at the time wrote to the university’s vice chancellor, Levi Nyagura saying the university’s decision to give a doctorate to Grace had reduced its degrees to "a laughing stock".