Slovenia’s main opposition leader was among five people briefly detained Thursday in an alleged multimillion-dollar corruption investigation into the building of a sports complex, investigators said. Police searched Zoran Jankovic’s house and his office in the capital, Ljubliana, where he is also mayor. His son, Jure Jankovic, a businessman, was also detained. Robert Crepinko, head of the National Bureau of Investigation, said police searched 23 homes in Slovenia in the probe into suspected irregularities with the sports hall in Ljubljana.
‘‘The focus of the investigation is financial transactions worth more than €10 million ($12.8 million),’’ he said. Crepinko gave no other details. Media in Slovenia reported that Jankovic is suspected of abuse of office and of siphoning city funds to companies with ties to himself and his family.