Chinese property developers and their controlling shareholders will be banned from participating in land auctions if they are found guilty of illegal activities, the government warned Monday.

Developers who have failed to start developing land a year after acquiring a plot at auction would be barred from bidding for additional land until they rectify their irregularities, said a statement on the Ministry of Land and Resources website.

The measure also applied to developers found forging documents to acquire land and conducting illegal transfers of land for profit, said the statement jointly issued with the Ministry of Housing and Urban-Rural Development.

The tighter controls were "an important task to curb gains in home prices and continue reasonable correction in housing and land prices," the statement said.

The Ministry of Land and Resources launched an investigation campaign into land hoarding from March to July this year. A total of 3,070 cases of land misuse nationwide were reported as of the end of May, with 2,815 cases of land, covering 169,500 mu (11,300 hectares), lying idle, Liao Yonglin, an official with the ministry, said in August.

Regulations already allow the government to reclaim land from developers without a refund if the plot remains unused for more than two years. If the land is left idle for more than a year and less than two years, land developers can face a surcharge of 20 percent of the land transfer fee.

The move extended government efforts to cool the property market since April this year, including curbing lending to developers, limiting loans for third-home purchases and requiring higher down-payments for second-home purchases.

Home prices in 70 major cities rose 9.3 percent year on year in August, the slowest monthly increase this year.

On a year-on-year basis, China's home prices rose 7.8 percent in December last year, 9.8 percent in January this year, 10.7 percent in February, 11.7 percent in March, 12.8 percent in April, 12.4 percent in May, 11.4 percent in June and 10.3 percent in July.

The statement said the government would also accelerate the supply of affordable housing, public housing projects and smaller homes.

Local governments must allocate at least 70 percent of land offered at auction to affordable housing, or small and medium-sized apartments, said the statement. Those that fail to do so should not offer land for large and luxury homes, it said.

Construction planning and land authorities should grant approvals within 10 days of applications for government-supported projects, the statement said.