China's deputy public security minister, who was placed in charge of security affairs for protest-wracked Hong Kong in 2017, is being investigated by the country's anti-graft body for alleged corruption.
Sun Lijun was being investigated for "serious violations of discipline and the law" -– a euphemism for corruption -- according to China's Central Commission for Discipline Inspection.
The notice, published late Sunday, did not give details on the alleged wrongdoings.
Sun, 51, was last seen in public in early March in Wuhan, the city at the epicentre of China's coronavirus outbreak, the official People's Public Security Daily reported.
He had also visited Hubei province -- where nearly 3,900 have died from COVID-19 -- in February to encourage frontline police officers, state-run Xinhua news agency reported.
On top of his main role, Sun was appointed director of the Hong Kong, Macao and Taiwan office under the ministry of public security in December 2017.
Hong Kong was shaken by widespread and sometimes violent street protests last year, sparked by a now-abandoned proposal to allow extraditions from the semi-autonomous city to the Chinese mainland.
A growing number of Communist Party cadres have been caught in President Xi Jinping's anti-corruption campaign, which critics say has also served as a way to remove the leader's political enemies.
The graft probe targeting Sun follows the high-profile arrest of Meng Hongwei, the former Interpol president who also served as a deputy security minister in China.
Meng disappeared during a trip to China from France in September 2018, and was jailed for more than 13 years in January after pleading guilty to abusing his position and taking over $2 million in bribes.
The Communist Party committee of the public security ministry –- an important decision-making body of which Sun was a member -- said it "unanimously expressed its firm support" for the investigation into Sun.
"Sun's investigation on suspicion of serious violations of discipline and law is the inevitable result of his long-term disregard of the party's political discipline and rules, and his failure to observe discipline, disregard rules, ignorance, and wanton behavior," the committee said in a statement.