Land authorities in six Chinese cities including Beijing have illegally charged 1.1 billion yuan (US$146.7 million) on enterprises so far this year, adding fuel to the nation's soaring housing prices.

This was discovered by the National Development and Reform Commission, China's top planning body, during examinations of charges on businesses in Beijing, Shijiazhuang, Jinan, Guangzhou, Chengdu and Xi'an, the Beijing News said Saturday.

The amount was well beyond the total illegal charges collected by eight departments for the whole year of 2006, said Li Lei, head of NDRC's Price Supervision Department.

Quoting estimates by the land authorities, which say land costs account for 20 percent to 50 percent of the housing prices, Li said the behavior of these authorities has made the runaway housing prices worse.

Despite by rounds after rounds of government curbs including restrictions on housing ownership by foreigners, housing prices have rocketed in China over the last few years, to the agony of ordinary people.

Land authorities are not alone in overcharging enterprises. The commission found in May that urban construction departments have overcharged 216 million yuan (US$28.8 million) from construction firms.

"The illegal charges have added fuel to the rising house price, " Li said.

The housing prices in 70 large- and medium-sized cities in China went up by 7.1 percent in June over the same period last year, according to official statistics.