One of Africa's most prestigious universities is investigating how 300 students managed to get their degree results changed.
Uganda's Makerere University discovered that the students' marks had been tampered with in 2015.
It is thought that some people responsible for managing the results system were behind the changes, Vice-Chancellor Barnabas Nawangwe said.
They are being investigated and the students' degrees have been withheld.
The BBC's Patience Atuhaire in the capital, Kampala, says that the university-wide investigation will compare questionable degrees with students' result papers and exam results submitted by lecturers and colleges to their deans, going back to 2011. It will also look at the academic registrar's records.
Two years ago, 600 students from the College of Humanities and Social Sciences were removed from the graduation list, after a whistle-blower pointed out that their marks were lower than the pass mark for their courses.
The university, in Kampala, is one of the most well known on the continent ands has 40,000 students, many from outside the country.
Among its graduates are a number of current and former heads of state including Tanzania's first president, Julius Nyerere, and Kenyan author Ngugi wa Thiong'o.
But Professor Nawangwe told the BBC's Focus on Africa programme that the attempted cheating would not damage the university's integrity as "we were able to arrest the situation before anyone was able to get our academic papers".
He said that the staff suspected of being involved have been suspended and security measures are now in place to "make it extremely difficult for anyone to do that kind of thing again".