Why an 'invitation to tea' is cause for fear in China

Chinese netizens have creatively used the euphemism 'invitation to tea' to refer to someone being summoned or investigated by law enforcement departments for suspected illegal activities. China's ministry of state security released a list of '10 Cups of Tea', which includes offences like endangering national security and illegally acquiring state secrets, to warn against potential probes.

source https://timesofindia.indiatimes.com/world/china/the-meaning-of-invitation-to-tea-and-its-implications-in-china/articleshow/107291449.cms