BEIJING (Reuters) - A senior military officer who sits on China’s powerful Central Military Commission, which is headed by President Xi Jinping, is being questioned on suspicion of corruption, three sources familiar with the situation said.

FILE PHOTO: Chief of the general staff of the Chinese People's Liberation Army Gen. Fang Fenghui attends a meeting with Joint Chiefs Chairman Gen. Joseph Dunford (not pictured) at the Bayi Building in Beijing, China August 15, 2017. REUTERS/Thomas Peter

Fang Fenghui had been chief of the Joint Staff Department of the People’s Liberation Army until he was replaced late last month, with no official word on what had happened to him, whether he had taken up another post, or had retired.

“Fang Fenghui was questioned regarding economic problems,” a source with ties to the leadership told Reuters. “Economic problems” is often used as a euphemism for corruption in China.

Another source familiar with the situation said: “They’ve detained him.”

“It’s on suspicion of corruption,” said the second source, who also spoke on condition of anonymity.

The third source also confirmed Fang was being questioned.

It was not clear if the questioning would lead to a formal indictment. Chinese officials are sometimes questioned informally and then released.

China’s Defence Ministry did not respond to a request for comment on whether Fang had been detained or was being questioned.

It was also not possible to reach Fang or a representative for comment and it was unclear if he had been allowed to retain a lawyer.

Fighting corruption in the military has been a focus of Xi’s broader crackdown on deep-seated graft, a problem he has warned is so serious that it could affect the ruling Communist Party’s grip on power.

Dozens of officers have been investigated and jailed, including Xu Caihou and Guo Boxiong, both former vice chairmen of the Central Military Commission. Guo was jailed for life last year. Xu died of cancer in 2015 before he could face trial.

MILITARY RESHUFFLE

The 11-man Central Military Commission is in overall charge of China’s military, headed by Xi and made up of the most senior military officers.

At a monthly news conference last week, defense ministry spokesman Ren Guoqiang declined to comment on where Fang was or if he had been given another position. Wen asked about Fang, Ren said: “we are not aware of it.”

Fang turns 67 next year, an age at which many Chinese officials retire.

His last public appearance was on Aug. 21, when he met a senior Thai military officer in Beijing. He also met Joseph Dunford, chairman of the U.S. Joint Chiefs of Staff, on Aug. 15.

Fang was also part of Xi’s delegation that met U.S. President Donald Trump at Trump’s Mar-a-Lago estate in Florida in April.

The questioning of Fang comes ahead of next month’s once-every-five-years Communist Party Congress, at which Xi will look to further cement his tight grip on power.

The party has already begun a military reshuffle connected with the Congress, announcing last week new chiefs for the army and the air force.

The official People’s Liberation Army Daily said last month the military needed to be on its guard against corruption rearing its head again, warning that “the arrow cannot be put back in the quiver”.

Serving and retired officers have said graft in the armed forces is so pervasive it could undermine China’s ability to wage war.

The anti-graft drive comes as Xi steps up efforts to modernize forces that are projecting power across the disputed waters of the East and South China Seas, although China has not fought a war in decades.