The U.S. government believes Chinese defense minister Li Shangfu is under investigation and has been stripped of his responsibilities, the Financial Times reported Thursday, as the general has not been seen in public for more than two weeks.

Reuters said Thursday that Li abruptly pulled out of a meeting with Vietnamese defense leaders last week. Li's disappearance from public view follows the removal of Qin Gang as Chinese foreign minister in July after a mysterious one-month absence from public duties.

Chinese defense minister Li Shangfu. (Kyodo) 

Two top generals at the Chinese military's Rocket Force, which oversees a unit handling nuclear weapons, were also replaced in July, fueling speculation that they were investigated over corruption.

U.S. Ambassador to Japan Rahm Emanuel posted on social media platform X, formerly known as Twitter, on Friday that Li might be under house arrest, with the hashtag "#MysteryInBeijingBuilding."

The envoy had also sarcastically said in a Sept. 8 post that the Cabinet lineup of Chinese President Xi Jinping is "now resembling Agatha Christie's novel And Then There Were None," referring to the mysterious absences of Li, Qin and the Rocket Force personnel.

The Financial Times said U.S. officials briefed on the intelligence did not say what had led President Joe Biden's administration to conclude that Li was being probed.

Reuters, meanwhile, quoted Vietnamese officials as saying Li skipped an annual gathering on defense cooperation scheduled for Sept. 7-8 on the Southeast Asian country's border with China due to a "health condition."

Asked about Li's situation at a press conference on Friday, Chinese Foreign Ministry spokeswoman Mao Ning said that she is "not aware" of any "relevant information."

The defense minister was last seen in public on Aug. 29, when he delivered a speech to a security forum with African nations in Beijing.

During a session of the National People's Congress in March, Li was appointed as defense minister. In June, he held talks with then Japanese Defense Minister Yasukazu Hamada in Singapore on the sidelines of the Asia Security Summit, known as the Shangri-La Dialogue.

Li was sanctioned by the United States in 2018 over Chinese weapons purchases from Russia. China rejected a U.S. proposal for official talks between Li and Defense Secretary Lloyd Austin in Singapore, urging Washington to lift the sanctions.

Related coverage:

Qin removed from China foreign minister post, Wang reinstated: media

China open to dialogue with U.S., says conflict would cause disaster

U.S. warns impact of conflict in Taiwan Strait would be devastating