France has opened an investigation into the disappearance of the Chinese president of the International Police Organization, Meng Hongwei, after he went missing on a visit to China.

The Interpol chief’s wife, who is living in France, where the international law enforcement organization is based, reported him missing on Friday, according to multiple media reports.

French officials said that members of Meng’s family have not heard from him since he departed from the French city of Lyon on September 25, according to a report from the BBC.

Sources quoted by The South China Morning Post said he was “taken away” for questioning in China.

“France is puzzled about the situation of Interpol’s president and concerned about the threats made to his wife,” the French interior ministry was quoted by BBC as saying.

Interpol released a vague statement that it was aware of the “alleged disappearance,” but said the matter should be resolved by “relevant authorities in France and China.”

As of yet there is no indication as to why Meng would be under investigation by authorities in Beijing. The Chinese law enforcement official’s election as president of Interpol in 2016 was seen at the time as a victory for Beijing, and a development that lended legitimacy to the international reputation of China’s criminal justice system.

Though few details have emerged, the mysterious circumstances of Meng’s disappearance have already prompted criticisms of Chinese authorities’ lack of transparency.