South Korea's money supply growth accelerated for two months in a row amid the all-time low borrowing costs, central bank data showed Tuesday.

The M2, dubbed broad money, increased 6.6 percent in April from a year earlier, according to the Bank of Korea (BOK). The M2 growth rate picked up from 5.9 percent in February to 6.2 percent in March, before going faster in April.

The faster money supply increase was attributable to the record-low policy rate. The Bok cut its benchmark rate from 3.25 percent in July 2012 to an all-time low of 1.25 percent in June last year.

The M1, also called narrow money, jumped 9.9 percent in the cited period.

The M1 covers currency in circulation, demand deposits and transferable savings deposits equivalent to cash. The M2 adds money market fund, money trust, time deposit and financial products that mature in less than two years to M1.

Liquidity of financial institutions, called Lf, advanced 7.4 percent in April from a year ago. The on-year growth of liquidity aggregate, the broadest measure of money supply, was 7.7 percent.

The Lf includes financial products with a maturity of more than two years and liquidity at insurers and brokerages along with M2. The liquidity aggregate adds state and corporate bonds to the Lf.