China's taxation authorities have ordered local bureaus to plug loopholes in the country's collecting of personal income taxes from high-income citizens by strengthening coordination with other departments.

Income from the transfer of equity and houses, derived from auctions, interest returns, stock dividends and bonuses would become the main targets of taxation improvements, said the State Administration of Taxation (SAT) in a statement on its website.

The STA said it would enhance cooperation with administrations for industry and commerce to step up taxation on transfer of equity in non-listed companies, and work with various departments to improve taxation on transfer of equity in listed firms.

"Taxation authorities should enhance contact with auction houses in order to be given information about the sources of income derived from auctions and urge auction houses to pay taxes on behalf of income owners," said the STA.

Tax authorities would also trace the income of investors of enterprises that have continuously made profits without distributing stock dividend or bonuses, the STA said in a statement on its website.