Over decades as a Chinese technocrat, Liu Tienan rose to become one of the top planners of the world's second-largest economy, but was brought down by a former lover.

Even as deputy director of the National Development and Reform Commission (NDRC), Liu -- whose given name literally means "iron man" -- was a bureaucrat with little or no public profile.

That changed when his mistress -- identified only by her surname Xu -- detailed shady business deals, fake academic credentials and death threats to Luo Changping, the deputy editor of business magazine Caijing.

Luo reported a litany of her accusations on his Sina Weibo microblog, including that Liu had formed an "official-businessman alliance" with an entrepreneur, had sought an undeserved degree from a university and that she received death threats after they fell out.

Liu's wife and son held shares in the businessman's company, and he wired "huge amounts of money" into foreign currency accounts held by the son "multiple times", the journalist added.

Luo was later moved to a different post in his organisation, but the Communist Party's anti-corruption watchdog had already announced Liu was being investigated for "grave violations of discipline" -- code for corruption.

He was convicted Wednesday of accepting bribes worth $6 million from several businessmen, and sentenced to life in prison.

At his trial in September the court heard the bribes included cash and gifts for the son, among them a villa in Beijing and a Porsche.

- 'Oil faction' -

Liu was born in Beijing in 1954 and studied at Iron and Steel College during the twilight years of the Cultural Revolution, a decade in which nearly all formal schooling was suspended. Little is known about his family life or what he did before he started working for the government.

He began his career in 1983 in what was then known as the State Planning Commission, which oversaw China's centrally managed economy before the country introduced market reforms.

After a short stint as an economic attache in Tokyo, he returned to the commission, which by then had been renamed and whose approval was required for nearly all large-scale industrial projects.

A career technocrat, Liu eventually rose to deputy director of the NDRC and head of the National Energy Administration.

Analysts say his position overseeing the energy industry meant he developed close relationship with former security czar Zhou Yongkang and former head of China National Petroleum Corporation Jiang Jiemin, both now under investigation for corruption.

Zhou and Jiang are central figures in what some analysts have termed the "oil faction" within the Communist Party, a network of influential politicians who have ties with China's powerful and lucrative petroleum industry.

While the circumstances of their corruption investigations are surrounded by political intrigue, Liu's downfall was far more public.

Following Liu's arrest, many in China questioned the competence of local anti-corruption bureaux as an increasing number of cadres were brought down by their jilted mistresses, rather than official investigations.

The speculation prompted the People's Daily, the Communist Party's flagship newspaper, to reflect on the crisis of confidence.

"Some people have said that the anti-corruption departments at all levels perform worse than the mistresses," it said in an editorial last year.

"Although it's a joke, it reflects a serious question: Whom should the anti-corruption effort depend on?"