Zhang, 66, a former member of the Central Military Commission and former head of its Political Work Department, hanged himself at home during the ongoing investigation, the ministry said in a news release.

He has become the first member of the CMC, the country's top military authority, and the highest-ranking officer with the People's Liberation Army to have taken his own life.

The release said he was placed under investigation on Aug 28 over involvement in the cases of Guo Boxiong and Xu Caihou, both former CMC vice-chairmen disgraced by corruption probes. Investigators later found he had "severely violated Party regulations and State laws" and had "given and taken bribes".

Guo was sentenced to life in prison in July 2016 for taking huge amounts of money as bribes and taking advantage of his position to assist the promotion and reassignment of others.

Xu died of cancer in March 2015 while under investigation for allegedly accepting large sums as bribes, according to military prosecutors.

A native of Hebei province, Zhang was recruited as a soldier by the PLA in 1968. His early career in the military remains undisclosed. Official records show he began to undertake political work in the PLA Ground Force in the mid-1990s.

He was appointed political commissar of the former Guangzhou Military Command in 2007 and later that year was elected a member of the 17th Central Committee of the Communist Party of China.

In October 2012, Zhang was named head of the former PLA General Political Department, predecessor of the CMC Political Work Department.

A month later, he was elected a member of the 18th CPC Central Committee and gained a seat in the CMC.

The last time Zhang appeared in public as chief of the Political Work Department was on Aug 3, when he addressed a meeting in Beijing attended by the military's publicity officials.

In early September, PLA Daily reported that Zhang had been replaced by General Miao Hua, who previously was political commissar of the PLA Navy. No explanation was given at that time.

An editorial published by PLA Daily on its website on Tuesday said Zhang put an end to his life in a "shameful way".

It said there is no hideout inside the military for corrupt officers, adding the investigation shows the determination of the CPC Central Committee and the CMC to purify the military.