An offshore tax evasion probe has found that the amount of taxes that South Koreans evaded paying by concealing their assets and income in offshore accounts amounted to a record of some one-point-three trillion won last year.

Lawmaker Park Myung-jae of the main opposition Liberty Korea Party unveiled the latest data on Monday which he acquired from the National Tax Service.

Such back taxes had amounted to only 150 billion won in 2008, but the figure grew to some 502 billion won in 2010 and then to 964 billion in 2011 before topping one trillion won in 2013.

The data found that the percentage of cases in which offshore tax evaders objected to tax probes also grew from 17-point-one percent in 2013 to nearly 24 percent last year.

In particular, people who had evaded large amounts of taxes abroad had the tendency to protest against paying back taxes.

Out of the total amount of offshore taxes evaded last year, the government was estimated to have collected some one trillion won.

Park said that offshore tax evasion is increasingly becoming more serious but the National Tax Service’s handling of the problem is lukewarm.