Zhang Yang, a former member of the powerful Central Military Commission, was being investigated over links to fallen generals Guo Boxiong and Xu Caihou, the official Xinhua news agency said.
The probe verified that Zhang Yang "gravely violated discipline", was "suspected of giving and taking bribes" and the origin of a huge amount of assets was unclear, Xinhua said, citing the commission.
"On the afternoon of Nov. 23, Zhang Yang hanged himself at home," the agency said.
Sources had told Reuters that Zhang, who was director of the military's Political Work Department, had been subject to an investigation, but the government had not announced it.
China's military, the world's largest and currently undergoing an ambitious modernisation campaign, has been an important focus of President Xi Jinping's campaign against deep-seated corruption since he took power five years ago.
Serving and retired officers have said graft in the armed forces is so pervasive it could undermine China's ability to wage war.
A commentary carried on both the Defence Ministry and military's official websites said the CMC decided on Aug. 28 to investigate Zhang, who had "lost his moral bottom line" and used suicide as a means to "escape punishment from the party and country", an "extremely abominable action".
"This former general of high position and great power used this shameful way to end his own life," the commentary said.
"He would exhort loyalty but be corrupt behind others' backs, a typical 'two-faced person'," it said.
(Reporting by Michael Martina and Philip Wen; Editing by Clarence Fernandez and Nick Macfie)