The son of retired Chinese internal security chief Zhou Yongkang is under arrest and may be charged with corruption, the South China Morning Post said Friday.
Zhou Bin, 41, has been in touch with lawyers about preparing a defense, the Hong Kong daily said, citing unnamed officials.
The younger Zhou is suspected of illicit activities in China's oil industry - where his father's career began - and in Sichuan province, effectively run by Zhou Yongkang in the early 2000s.
Zhou Yongkang was minister of public safety from 2002-2007, when he joined the Communist Party's Politburo Standing Committee, the seven-member body that makes all important policy decisions.
Party leaders agreed last year to investigate Zhou Yongkang for suspected economic crimes, the Morning Post said.
No current or former member of the Politburo Standing Committee has ever been the subject of a formal judicial probe.
While the Chinese government declines to confirm that it is investigating the elder Zhou, a number of his political allies have lost their posts in recent months.
The erstwhile internal security boss was also an ally of disgraced Chongqing municipal party secretary Bo Xilai, now serving a life sentence for bribery, corruption and abuse of power.
The 71-year-old Zhou Yongkang retains a seat on the party Politburo. EFE