Chinese public security authorities have placed South Korean midfielder Son Jun-ho under formal arrest on suspicion of having taken a bribe, following the expiration of his detention period, local media outlets reported on Sunday, citing a source familiar with the case.

The midfielder, who played at last year’s FIFA World Cup, and plays for Shandong Taishan in the Chinese Super League, has been detained in the northeastern Chinese province of Liaoning since mid-May on bribery charges.

"Since the period of detention expired Saturday, the public authorities who have been investigating Son have received approval for his arrest from the prosecution. The switch to an investigation under arrest means that the public security authorities have begun taking formal legal steps against Son," the source told the Yonhap News Agency.

Once an arrest is approved, public security authorities typically take around two months to conduct a more profound investigation before taking steps for an indictment. However, it can take up to several months before an indictment if there are significant issues to be addressed.

Although all the details have not been fully revealed, local media reported that Son's case may be related to alleged involvement in bribe-taking. The Chinese authorities have investigated match-fixing allegations involving coach Hao Wei and other players on Son's team. Chinese football has struggled for years to eradicate match-fixing and misconduct in the sport.

Son, 31, a South Korean midfielder representing the South Korean national team and Shandong Taishan FC in the Chinese Super League, joined Shandong Taishan in 2021 on a four-year contract. He played in three of South Korea's four games at last year’s World Cup in Qatar.