Amid reports that the Chinese authorities have seized billions of dollars in assets linked to former security czar Zhou Yongkang, an investigation into his political allies, relatives, and business interests recently widened to include his second brother and family, a relative confirmed on Wednesday.
Zhu Qindi, wife of Zhou's nephew Zhou Xiaohua, said Zhou's second brother Zhou Yuanqing, his wife, and the couple's son Zhou Feng were recently detained by "people who came from Beijing" as part of a corruption investigation she said was a show of political force on the part of President Xi Jinping.
Speculation has been mounting for months that the ruling Chinese Communist Party may be getting ready to charge Zhou, 71, a former member of the party's elite Politburo Standing Committee, with corruption and abuse of power.
But according to Zhu, who spoke to RFA's Cantonese Service in her hometown of Wuxi in the eastern province of Jiangsu, the charges against Zhou are "trumped up" and part of a power struggle at the heart of the party.
"Those who know what's going on are telling the truth, and those who don't are talking rubbish," Zhu said, in an apparent reference to commentators who seek a political motive for the probe and those who take it at face value.
She said the family was being unfairly targeted by the current administration.
"If they are going to go after people, they shouldn't bully us like this; we're Communist Party members, after all," Zhu said. "They should take a factual approach, and not lump apples together with oranges."
"This comes of some people getting to high office when they're still young, and thinking they're God almighty."
Zhou, who was once a political mentor to jailed former Chongqing party chief Bo Xilai, stepped down from his post as Politburo standing committee member and head of the political and legal affairs commission in November 2012, where he wielded huge power, political analysts say.
His post has since been downgraded to report to the all-powerful Politburo standing committee.
Some analysts say the probe is a form of political retaliation after Zhou angered Xi and other high-ranking leaders by opposing the ouster of Bo Xilai, who was jailed for life in September for corruption and abuse of power.
If Xi's administration, which has vowed to go after high-ranking "tigers" in a graft crackdown begun last year, goes public with the probe, Zhou will become the most senior Chinese politician to be ensnared in a graft scandal in the history of Communist Party rule.
Last month, official media mentioned the investigation linked to Zhou for the first time since unconfirmed reports first began to emerge last year.
Meanwhile, Chinese authorities have seized assets worth at least 90 billion yuan (U.S.$14.5 billion) from Zhou's family members and associates, Reuters reported on Monday.
Quoting two sources who have been briefed on the investigation, it said more than 300 of Zhou's relatives, political allies, proteges and staff have been taken into custody or questioned in the past four months.
However, veteran Beijing journalist Gao Yu said she doubts that investigators have enough evidence to pursue a conviction publicly through Chinese courts.
"I don't expect they will use the rule of law to pursue Zhou Yongkang; it's very likely that this will be dealt with internally by the party," Gao said. "We still don't know what they are able to pin on him."
"My guess is that the authorities haven't found evidence of corruption yet. There were rumors that he killed his wife, but they [probably] can't find evidence for that either," she said.
Beijing-based lawyer Li Heping said that while China is abuzz with speculation over Zhou's eventual fate, most people are waiting to see whether the government will make details public of his and his family's assets.
"Everyone's saying that if they don't make the details of his assets public, then this anti-corruption campaign will be useless," Li said.
Suspects in the ongoing probe come from a tangled and often informal network of power and influence headed by Zhou, including the state-run petroleum industry, Sichuan provincial government, the nationwide Communist Party political and legal affairs committees, as well as land and resources bureau and propaganda officials, sources say.
Four of Zhou's former political secretaries have been detained for investigation to date.
Reported by Yu Lushi, Bi Zimo, Ho Shan, and Wei Ling for RFA's Cantonese Service and by Yang Jiadai for the Mandarin Service. Translated and written in English by Luisetta Mudie.