BEIJING/PARIS (Reuters) - The wife of former Interpol chief Meng Hongwei has hired two law firms to help track down her husband, who has been missing since traveling back to his native China more than a month ago, but China said she had refused offers to talk to him by telephone.

FILE PHOTO: INTERPOL President Meng Hongwei poses during a visit to the headquarters of International Police Organisation in Lyon, France, May 8, 2018. Jeff Pachoud/Pool via Reuters/File Photo

Days after Meng’s wife reported him missing, prompting France to open an inquiry, China said he was under investigation for bribery and other violations. Interpol, based in the French city of Lyon, said Meng had resigned as president.

But no word has been heard from Meng himself since he sent his wife a WhatsApp message on Sept. 25 saying “wait for my call”. Grace Meng said she had decided to retain the law firms in London and Paris to pursue her husband’s case.

“Since my husband disappeared, people from all over the world have asked what they can do to help,” she said in an emailed statement, saying the firm of Marsigny Avocats and UK-based Lindeborg Counsellors had been retained.

“Above all, I urge everyone to raise their voice in asking China to respect our family’s fundamental human rights,” she said. “His disappearance could not be for anything other than political reasons.”

It is unclear where Meng, 64, is being held and it has not been possible for Reuters to reach him for comment. It is also unclear if he has been allowed to retain legal representation.

Speaking in Beijing on Tuesday, Chinese Foreign Ministry spokesman Lu Kang said China protects the legitimate rights of all Chinese citizens, no matter what situation they find themselves in.

China has already told his wife that if she wants to contact him by telephone then that can be arranged “at any time”, Lu told a daily news briefing.

“But Meng Hongwei’s wife, on the one hand says she doesn’t know where he is, and on the other hand refuses to contact him by telephone. Why? We don’t know.”

French authorities have said that Meng’s wife and their children are under police protection in Lyon after receiving threats.

Meng, a deputy minister of public security in China, became president of Interpol in late 2016 amid a broader effort by China to secure leadership posts in international organizations.

Presidents of the international police organization are seconded from their national administrations. They remain in their home post while representing the body.