China's National Bureau of Statistics has accused a county government in southern China of faking economic data by coercing local companies to boost industrial output figures, state media have reported.

Luliang county in southern Yunnan province pressured 28 local companies to report 6.34bn yuan (£665m) of industrial output last year, while according to "initial calculations" the true figure was less than half of that, the state newswire Xinhua reported on Thursday night.

"Companies complained that if they did not fraudulently report higher data their reports would be returned by local government departments," it said, citing a National Bureau of Statistics report. "They also said that fake reports would ensure they would enjoy favourable policies such as securing bank loans."

The county government itself reported fake investment data, Xinhua added.

Analysts say that phoney economic data is nearly ubiquitous in China, as officials are promoted based on their ability to present favourable numbers.

"You have an incentive system that encourages the falsification of data," said Fraser Howie, the co-author of Red Capitalism: The Fragile Financial Foundation of China's Extraordinary Rise.

"We known that for literally decades provincial GDP figures have never totalled the national GDP figures – you have a fundamental mismatch of those numbers."

"Anybody who's working with Chinese statistics runs up against problems, inconstancies, and incomplete data," Howie added. "There are just black holes in information gathering."

Howie said that while false data was a long-running national problem, Chinese authorities may launch selective crackdowns every few months to demonstrate vigilance. "It could be that this is a particularly egregious case, it could be that there's political infighting, it could be that this leaked somewhere else first," he said.

He drew a parallel to President Xi Jinping's anti-corruption drive, which critics have dismissed both as lip service and as a political purge.

"Its like the corruption thing – they're not going after nobody, but they're certainly not going after everybody," he said. "Yunnan is far away, nobody really goes there, nobody really cares. It's not like this happened right in Beijing, at the heart of things."