A senior official with China's powerful planning agency confirmed media reports that the country was studying a possible nationwide property tax but had no specific plan, the China Business News reported on Thursday.

It also said Shanghai was considering introducing the tax in the city on a trial basis.

Previous media reports that China could expand the property tax, which is now levied on commercial property, to cover the residential sector have driven down the main stock index by more than 20 percent so far this year.

The newspaper, citing an unnamed senior official at the National Development and Reform Commission, said there was no timetable yet for any expanded tax rollout.

The official said China encouraged trials by local governments to launch the property tax but added there was no specific plan for a nationwide program, according to the newspaper.

China introduced a series of fresh steps to curb excessive housing price rises in some cities in April, including higher down payments and mortgage rates.

These measures have driven down the number of transactions but prices have remained near record levels.