The Chinese Communist Party announced late Sunday that the missing president of Interpol, Meng Hongwei, was under investigation on “suspicion of violating the law” and was “under the supervision” of an anticorruption watchdog tied to the party.
The announcement that Mr. Meng, a Chinese national, was being detained was posted online by the Central Commission for Discipline Inspection, the party’s watchdog against graft and political disloyalty, on Sunday night.
The statement did not give further details.
It came hours after Mr. Meng’s wife, Grace, told reporters in Lyon, France, where the two were living, that before her husband vanished on a trip to his native China, he had sent her a phone message with an emoticon of a knife, which she said hinted he was in danger.
It also came a day after Interpol demanded answers from the Chinese government on the whereabouts of Mr. Meng, who has been missing since Thursday.
Mr. Meng’s wife said she has not heard from him since he left Lyon, the city in central France where Interpol has its headquarters, in September.
France has begun its own investigation, with the authorities saying that he had boarded a plane and arrived in China, but that his subsequent whereabouts was unknown.
In addition to serving as president of the international crime fighting body, which is based in France, Mr. Meng is also vice minister in the Chinese Ministry of Public Security.
The central commission can detain party officials for months or years while carrying out an investigation. The commission often concludes an investigation by stripping the official of party membership, stating the official’s violations of party regulations and referring the official to the justice system for criminal prosecution.
Since Xi Jinping took power as president of China, the commission has gone on a wide-ranging anticorruption campaign that has touched every level of the party.
The detention of Mr. Meng, 64, is a stunning move by the party, even by the standards of the increasingly authoritarian system under Mr. Xi’s rule. China seeks legitimacy and a leadership role in international organizations, and Mr. Meng’s appointment in November 2016 as the president of Interpol, the first one from China, was seen by many as a significant step in that direction.
His detention means that internal party dynamics supersede any concern by the party about international legitimacy or transparency.
It is unclear what led to his apparent downfall — a power struggle within the party or an actual case of corruption that officials deemed to be beyond the pale.
There have been investigations of prominent figures in the anticorruption campaign. The most notable has been that of Zhou Yongkang, a former member of the elite Politburo Standing Committee and top security official. Many analysts of Chinese politics say Mr. Xi viewed Mr. Zhou as a rival and used the anticorruption campaign to imprison him.
In 2015, Mr. Zhou was convicted by a criminal court of abusing power, accepting bribes and revealing state secrets; he was sentenced to life in prison.
Over the summer, officials secretly detained Fan Bingbing, one of China’s most famous actresses. Her disappearance in July prompted wild speculation for months. Last week, Chinese officials announced that she had been fined almost $130 million for tax evasion.
Mr. Meng was last seen leaving Interpol headquarters in Lyon on Sept. 29, for his trip to China. His wife and children had moved with him to Lyon after his appointment.