The 2015 figure marks the highest level since 42.11 trillion won tallied in 2000, in the apparent aftermath of the 1997-1998 Asian financial crisis.

The amount had dipped to as low as 7.7 trillion won in 2007, but again shot up to 15.96 trillion won in 2009 following the outbreak of the global financial crisis the year before.

The increase in 2015 was mostly attributed to a large amount of corporate loans going sour, especially those extended to large companies.

In 2015, the overall amount of bank loans extended to large firms here only gained 7.28 trillion won to 436.78 trillion won.

However, the amount of non-performing loans extended to large companies increased by a greater margin of 7.33 trillion won to 17.69 trillion won, accounting for 4.05 percent of their total borrowing.

The tally also marks the fastest rate of rise in the amount of bad loans since 2008 when the FSS began compiling the related data.

Smaller firms, on the other hand, increased their total borrowing by over 50 trillion won in 2015 alone, but the amount of non-performing loans shrank 886 billion won from the previous year.

Household debt also spiked by over 44.6 trillion won, but the amount of bad loans slipped 612.5 billion won from a year earlier. (Yonhap)