The National Tax Service said Monday that it imposed penalties and back taxes of more than 743.8 billion won ($692.1 million) against conglomerates and wealthy individuals in the first half of this year.

It investigated 377 cases involving those suspected of evading taxes via offshore paper companies and borrowed-named accounts between January and June, the NTS noted via a press statement.

In 2012, the NTS looked into 771 cases, down from 869 in 2011.

The tax agency’s list of suspects included conglomerates with annual sales of more than 50 billion won, and executives, chaebol owners and their family members with assets or deposits of more than 3 billion won. Such assets included real estate holdings.

The NTS did not identify the names of individuals or conglomerates it investigated in the first half of this year.

This year’s case involved an unidentified manufacturing company that was found to have stashed borrowed money in a tax-haven account and recording it as accounts receivable in its financial statements.

Another company was found to have used its offshore funds to invest in domestic stocks and to have deposited its gains from equity investments in its tax-haven accounts without paying capital gains taxes.

The NTS said that it will use all of its available resources to track down those who had allegedly avoided paying taxes through offshore accounts.

This has been one of its top priorities along with normalizing the underground economy to seek tax revenue and help the Park Geun-hye administration to secure finances for welfare expansion.

Almost 700 people have reported to the authority their 6,718 offshore accounts worth 22.8 trillion won so far this year ― up 4 percent in terms of reports, 13 percent in the number of accounts and 23 percent in net worth, the NTS noted.

It investigated more than 3,200 wealthy individuals and their family members since 2008, and levied back taxes worth more than 4.2 trillion won.

By Park Hyong-ki (hkp@heraldcorp.com)