The Tokyo District Court sentenced a former gangster to a suspended three-year prison term Monday for attempting to blackmail pro baseball star Kazuhiro Kiyohara and his team, the Yomiuri Giants.

According to the court, 36-year-old Tatsuya Matsumoto conspired with others and got ahold of a photograph of Kiyohara playing golf with people linked to the underworld on New Year's Eve in 1996.

They then approached Kiyohara and the Giants with the photograph last spring and threatened to put the infielder in a position where he would never be able to play baseball again unless they paid money.

Two others, 32-year-old Kim Jun Gon -- a Yamaguchi-gumi mobster -- and a 28-year-old former gangster, have been arrested in connection with the case.

Kim's trial is under way, and he has maintained his innocence. The 28-year-old man, whose name was not provided, was sentenced to a suspended 18-month prison term.

Presiding Judge Masato Ito said the crime perpetrated by Matsumoto was "ignoble," because he falsified a letter claiming Kiyohara was involved in leaking information in connection with baseball gambling, even though all the defendant had was a photograph.