The Belarusian authorities are clamping down on the scope of higher degree dissertations in a move believed to be politically motivated.
The Higher Attestation Commission (VAK) has refused to confer qualifications and has banned individuals from teaching on the basis of the content of their work.
The moves have alarmed some Belarusian scholars who fear a return to the Soviet practice of forbidden themes and persons.
Dissertations for the degrees of candidate and doctor are defended before a panel of experts appointed by individual universities. But a degree cannot be conferred without the commission's approval.
Sviatlana Navumuk, a history lecturer at Brest University, has been refused a candidate's degree and banned from teaching because her dissertation was on the life and work of Kastus Yezavitau, a military leader in Belarus's struggle for independence in 1918-20.
Commission chairman Yauhien Novik said the text revealed that Ms Navumuk was unfit to have contact with young people.
Uladzimier Mikhniuk, Ms Navumuk's supervisor, was drawn into the dispute after lodging an appeal against the decision.
At that time, he was about to take over the post of director of the Institute of History of the Academy of Sciences.
The contract had been signed, and the outgoing director was clearing his office. But the day the appeal was lodged, Dr Mikhniuk's contract was cancelled.
Dr Mikhniuk could find work only in an unprestigious private law college.
In October he died suddenly, as have several leading academics who have clashed with the state in recent years.
The Institute of History's administration seems particularly sensitive to the commission's new line.
One of its staff, Yauhien Anishenka, was advised not to defend his doctoral dissertation on the Polish-Lithuanian Commonwealth of the 16th-18th centuries as the theme exhibited "Russophobia".
Mr Anishenka ignored the advice and successfully defended the work before an expert panel. He awaits the commission's decision.
A member of the institute had a dissertation on the medieval Prince Alhierd rejected because the aristocrat had advocated eastward expansion against Russia. Another had a dissertation on Napoleon's campaign of 1812 rejected because it did not refer to that war as "patriotic".
Other students have been warned off before completing their dissertations.