Japan's monetary base rose 27.6 percent in June from a year earlier to 85.43 trillion yen, the 17th straight month of expansion, the Bank of Japan said in a report released Tuesday.
The monetary base -- cash in circulation plus money in current accounts held by banks at the central bank -- increased 29.7 percent in May.
Growth in the monetary base began accelerating in March 2001, when the BOJ adopted a policy of quantitative monetary easing, in which it pumped up the money supply in a bid to turn around the faltering economy.
The fast pace of growth in the monetary base reflects the central bank's aggressive move to inject funds into the banking system to beat prolonged deflation.
The balance of banks' current accounts at the BOJ jumped 196 percent in June to 15.04 trillion yen, the report shows. The balance rose 208.6 percent in May.
The BOJ has maintained a policy of flexibly providing funds regardless of its 10 trillion yen to 15 trillion yen target for current account deposits held at the BOJ by commercial banks.