Zheng Xiaosong, the head of China's liaison office to Macau, had been suffering from depression, the Hong Kong and Macau Office of the Chinese government's State Council said in a statement, adding representatives of the Beijing government visited Macau to offer condolences. The statement did not elaborate further on the circumstances of his death.
Zheng, 59, was appointed to the Macau post in September 2017 and is a member of the ruling Communist Party's Central Committee, the largest of China's elite ruling bodies. He was previously the vice governor of the southeastern coastal province of Fujian.
The liaison office in Macau serves as a bridge between the local government and Beijing and has become increasingly influential in local affairs.
Like neighboring Hong Kong, Macau operates under China's "one country, two systems" policy and is ruled by a chief executive, who is chosen via an election but must get approval from Beijing to formally take office.
Macau Chief Executive Fernando Chui said in a statement that he was "shocked" about Zheng's death and expressed condolences. Hong Kong's Chief Executive Carrie Lam also issued a statement expressing "deep sorrow" for Zheng's death.
A statement published on Friday on the Macau liaison's office website showed that Zheng met with the head of a think tank the day before his death. During the meeting he emphasized the importance of supporting the local government and the one country, two systems policy to ensure Macau's continued development, the statement said.