The investigation over alleged legal breaches by Song Lin, the head of the State-owned enterprise China Resources Holdings, has encountered "resistance" and been put off for nearly a year, a Beijing newspaper has cited an insider as saying.

The Central Commission for Discipline Inspection of the Communist Party of China announced on Thursday night that Song was under investigation for suspected serious violations of discipline and law.

This happened just two days after Wang Wenzhi, a journalist of the Economic Information Daily affiliated with the Xinhua News Agency, blew the whistle on his verified microblog account, claiming Song was involved in corruption, dereliction of duty, and was suspected of keeping a mistress.

The reporter made his first disclosure of Song's alleged corruption in July last year. Although the authorities said they had received the report and were handling the case according to procedures, Song remained chairman of the Fortune Global 500 conglomerate with more than 420,000 employees until Thursday.

Last July, Wang made accusations online saying Song and other senior management staff at China Resources were involved in a fraudulent acquisition in 2010, causing billions of yuan in losses of State owned assets.

Senior officials ordered a probe, but it is said to have met resistance and been delayed for nearly a year, the Beijing News reported.

In Tuesday's report, Wang accused Song of keeping a woman named Yang Lijuan as his mistress, and arranged jobs for her at the Hong Kong and Shanghai branches of Swiss bank UBS, so that she could help him take bribes and launder illicit gains. Yang and her family own more than a billion yuan in assets, including large amounts of high-end real estate properties in Hong Kong and the Chinese mainland, as well as large deposits overseas, Wang said.

The Weibo report was removed later, with a new post saying "the central government's anti-corruption [drive] gives me courage. I just served my responsibility and duty as a citizen. I appreciate everyone's support and concern."

Wang said he had received threatening phone calls after he made the first report last year.

"The real-name online accusation is an important form of anti-corruption. The central government is quite supportive and has offered several online platforms for citizens to report corruption, " Zhu Lijia, director of the public research department of the Chinese Academy of Governance, told the Global Times.