TOKYO, April 7 (Reuters) - The Bank of Japan's (BOJ) holdings of Japanese government bonds (JGBs) hit a record at the end of March, the central bank's data showed on Friday.

The BOJ's holdings of JGBs stood at 582 trillion yen ($4.42 trillion) as of March 31, up 10.6% from a year earlier, and a record for the end of fiscal year since the central bank started publishing data in 2013.

The BOJ, which remains an outlier in a global wave of monetary tightening by central banks, was forced into massive bond buying to defend its policy cap on the 10-year Japanese government bond yield.

The massive bond buying distorted the JGB market by artificially suppressing part of the yield curve and causing illiquidity as the BOJ's ownership of benchmark bonds ballooned.

The central bank purchased a record 136 trillion yen in the year through March, almost double the amount in the previous year, separate data showed earlier this week.

($1 = 131.6800 yen) (Reporting by Junko Fujita; Editing by Muralikumar Anantharaman)