A businesswoman linked to China's disgraced railway minister faces charges of illegal business activities worth 180 billion yuan ($29 billion), state-run media said Monday, indicating far vaster industry corruption than previously revealed.

Ding Shumiao will face trial in Beijing for bribery and illegal business activities after she "intervened in bidding for dozens of railway projects", the China Daily reported, citing prosecutors.

The scale of the charges is larger than anything prosecutors have previously linked to corruption associated with the railway sector in China, where the high-speed network, now the world's longest, has been a flagship development project of the ruling Communist Party.

Former railway minister Liu Zhijun was given a suspended death sentence in July for accepting a total of 64.6 million yuan in bribes to help 11 people secure contracts and promotions.

The China Daily said Ding was accused of giving Liu more than 49 million yuan and arranging sexual favours for him, while Liu helped 23 businesses recommended by her to win contracts for more than 50 rail projects, the China Daily said.

The alleged total in inappropriate activities were equivalent to a quarter of China's entire national railway investment in 2010, it added.

Liu was sacked in 2011 after eight years in the post and being celebrated as "father" of China's vastly expanded rail network.

In March the railways ministry was disbanded, with its administrative functions handed to the transport ministry and its commercial role given to a new China Railway Corporation.

Last week a top rail official Zhang Shuguang was charged with accepting bribes worth 47 million yuan over 11 years, while another senior figure Su Shunhu stood trial for allegedly receiving 24 million yuan in bribes.

China's Communist leaders have vowed to crack down on rampant official corruption, which has stoked popular resentment.

The anti-corruption campaign has also targeted a former senior economics policymaker, top executives from a major state-owned oil firm and numerous low-ranking officials, but has not yet introduced systematic reforms.