Interpol's secretary general said on Thursday that the international police organisation's rules forbid him from probing into the fate of the Chinese government official who served as Interpol president for almost two years before he vanished during a trip to China.In his first public remarks about the disappearance of Meng Hongwei, Interpol Secretary General Juergen Stock said he "encouraged" Chinese authorities to provide information about Meng's location and legal status but can do no more.Meng became Interpol's president in November 2016. A new president will be elected to replace him during the organisation's general assembly in Dubai on November 18-21.Chinese authorities said they detained Meng, 64, on bribery charges, though his wife has described him as a victim of political persecution. He was China's vice minister of public security and appears to be the latest ranking Chinese official to have been caught in a sweeping purge under President Xi Jinping.Stock said his organisation learned of Meng's disappearance on October 5 via media reports that came out after Meng's wife said she had not heard from him since the end of September and reported him missing.Interpol contacted Beijing, asking for clarification, according to Stock. A high-level Chinese delegation arrived at Interpol's Lyon headquarters on October 7, reported that Meng had written a resignation letter and advised that he was no longer a delegate from China to Interpol — meaning he could no longer serve as president.China's Interpol office transmitted the resignation letter to Interpol headquarters later that day. Pressed on whether Interpol had assurances Meng actually wrote it or did so without duress, Stock hedged."There was no reason for me to (suspect) that anything was forced or wrong," he said.Interpol appeared to accept the Chinese delegation's explanation at face value and publicly announced that night that Meng had stepped down, without commenting on why or what happened.Stock cited the structure and nature of the 192-member organisation, which provides a platform for member nations to share information on criminal activities, and the vast needs it fulfills in trying to contain ballooning transnational crime. Interpol databases are queried 200 times each second by police around the world, he said."We are a rules-based organisation. That is very important to understand," Stock said, adding that the role of Interpol is "not to govern over member states"."We are not an investigative body," he said.Stock said he is in "constant" contact with the national central bureau in Beijing that serves as Interpol's point of contact in China. As secretary general, Stock manages Interpol's day-to-day activities, while the agency's elected president has a less hands-on, more symbolic role."We are strongly encouraging China" to come forth with details of Meng's case, Stock said. He suggested Chinese officials would "when the right moment comes".Meng's wife, Grace Meng, told The Associated Press last month that she received threats after her husband disappeared. She and their two children are under police protection in Lyon."There is no doubt this is a very regrettable situation," Stock said. "But on the other hand, we have to ensure day-to-day operations ... continue."He also conceded that Interpol must "mitigate negative impact" springing from Meng's disappearance.Interpol acts as a clearinghouse for national police services that want to hunt down suspects outside their borders. Governments have repeatedly tried to use Interpol to find political enemies, even though its charter explicitly proclaims its neutrality and prohibits use of police notices for political reasons.Stock said that ensuring the notices are not misused has been one of his priorities.