Leading officials within the Communist Party of China (CPC) will soon have to declare all assets and investments, as well as details on their family, as part of anti-graft measures to curb corruption.
High-ranking members will be ordered to disclose all housing and business dealings, along with the jobs of their spouses and children.
The CPC's Central Commission for Discipline Inspection announced the move during its Fourth Plenary Session in Beijing, which closed on Saturday.
The new rules will "beef up self-discipline and strengthen the management of officials whose spouses and children have emigrated abroad", Xinhua News Agency reported.
Around 4,000 corrupt officials fled the country with at least $50 billion between 1978 and 2003, showed a Ministry of Commerce report. Experts suspect the number is much higher.
Crooked officials often take bribes through companies run by the family in order to relocate their "dirty" money.
The commission has been monitoring job and college applications made by suspected Party officials and their relatives since July 2004, Xinhua reported.
On Saturday, the commission said it would punish anyone who sells or buys an official post, as well as those who attempt to rig election results.