Beijing: China's top spy Chief, Ma Jian, has been detained for alleged corruption as part of President Xi Jinping's widening crackdown on graft, a media report said on Monday.
Besides Ma, several of his close relatives were under the scanner, Hong Kong-based South China Morning Post reported.
Confirmation of Ma's detention is sure to cause a stir in the international intelligence community where he is well- known, the report said.
His detention virtually covers almost all the branches of the Chinese government where hundreds of officials have been held for corruption in the massive anti-graft campaign initiated by Xi to improve the credibility of the ruling Communist Party of China (CPC).
Ma's removal makes him the highest-ranking national security official to be investigated since the downfall of Zhou Yongkang, the country's former security czar, and signals a likely wave of high-level changes at the key intelligence agency, the report added.
It is not clear what triggered the probe, but it is believed to be linked to a high-profile anti-graft probe into the activities at the top of Founder Group, a Peking University-owned technology conglomerate.
Ma, the executive deputy minister of the omnipotent Ministry of State Security and who sources say was in charge of the mainland's massive counter-espionage operations, is believed to be close to Founder chief executive Li You who allegedly financed hugely profitable securities trades carried out by one of Ma's relatives.
Li has been involved in a high-profile spat with Beijing Zenith, a property developer with a mysterious background, but which is also the second-biggest shareholder in the conglomerate's Founder Securities unit.
Beijing Zenith publicly accused Founder executives of insider trading and misappropriating company assets to the tune of several billion yuan.
Group chairman Wei Xin, CEO Li and president Yu Li were taken away to "assist the authorities with their investigations", Founder said last week.
Ma is also closely linked to Ling Jihua, the one-time chief of staff to former president Hu Jintao who retired in 2013.
Ling was detained last month.