Answer
Babiš was investigated by the Czech police and the European Anti-Fraud Office (OLAF). The investigation was launched in 2016, after a whistleblower claimed that Babiš had illegally received EU funds for his farm. In 2017, OLAF concluded that there was sufficient evidence to warrant a criminal investigation, but the Czech police declined to open a case. The case was reopened in 2018, after Babiš was elected prime minister.