The Supreme Court has upheld a suspended prison term for a 27-year-old man who wrote graffiti on a public lavatory on grounds that caused damaged the building, legal sources said Thursday.

Writing graffiti is usually regarded as a violation of the Minor Offenses Law or city ordinances, but this is the first time the top court has ruled that the offense should be interpreted as damaging a building, which carries a penalty of up five years in prison.

The Supreme Court upheld a 14-month prison term, suspended for three years, that both the Tokyo District and High courts imposed for his painting of antiwar messages on a park lavatory in Tokyo.

Dismissing the defendant's appeal, presiding Justice Kunio Hamada of the court's No. 3 petty bench said it should be regarded as an act of "vandalism" as the defendant spoiled the appearance of the lavatory and made it difficult to restore it to its original state.

According to the Tokyo High Court, the defendant painted "Hansen" (Antiwar) and similar words on the outer wall of the lavatory in a park in Tokyo's Suginami Ward in April 2003 during the U.S.-led invasion of Iraq.

His lawyers argued the defendant's act "was within the (right of) freedom of expression," but the district court ruled "there were other ways to express" his antiwar stance.