Former Korea Baseball Organization batting champion Hae-yong Ma publishes a book claiming many foreign import players and some locals used steroids. The KBO instituted limited steroid testing in 2007 and had no global system due to cost concerns.

This Day In Baseball

On May 19, 2009 — Former Korea Baseball Organization batting champion Hae-yong Ma publishes a book claiming many foreign import players and some locals used steroids. The KBO instituted limited steroid testing in 2007 and had no global system due to cost concerns.

Source:
Baseball Reference May 19