The National Tax Service on Monday said it will step up audits of inheritance and gift tax evasion by the wealthy, investigating their stock holdings, bank deposits and real estate. The move aims to prevent the common practice of passing on property to heirs without paying the relevant tax.

Tax is often evaded through bank accounts or stock transactions under borrowed names; misappropriation of corporate funds by company owners or their relatives; and unauthorized transfer of profits from listed stocks to company owners' relatives.

The practice is spreading among the rich. Some 3,000 people are believed to have transferred their property illegally before their death in 2009. The number was 2,354 in 2006, 3,151 in 2007, and 3,703 in 2008. Some 98,600 people made over their property as gifts in 2007, up from 83,603 in 2008.