Croatia charged 23 people, including nine university professors, on Friday with taking bribes from students at Zagreb University in exchange for passes or higher marks in their exams.
"After three months of investigation, Croatia's police anti graft department (USKOK) charged 12 people from the faculty of economics, eight students and three intermediaries with giving or receiving bribes," an USKOK statement said.
Police raided the faculties of transport and economics last September and took several dozen university professors in for questioning in an investigation into alleged bribe taking, codenamed Index.
This is the second indictment in the case. A month ago 16 people were charged with corruption at the faculty of transport.
Among those charged at the economics faculty is a former head of parliament's committee for preventing conflicts of interest, a body that investigates officials' political and financial activities, state radio said.
A police spokesman was not immediately available for comment. Serious graft charges carry a possible penalty of between one and eight years in prison.
The European Union has made an intensified crackdown on corruption and organised crime a major requirement for Zagreb if it wants to wrap up accession talks by the end of this year.
Croatia has stepped up the fight against corruption in the last two years, but has completed relatively few trials and gained even fewer convictions.
Several graft trials are under way, including one involving alleged malpractice in the state privatisation fund.