The Supreme Court has denied bail to a prominent anti-U.S. base activist in Okinawa despite repeated calls for his release from human rights organizations and civic groups who deem his arrest political oppression.

In a decision dated Monday, the court rejected an appeal filed against a lower court's rejection on two occasions of a bail request for Hiroji Yamashiro, head of the Okinawa Peace Action Center.

Yamashiro, 64, has led groups opposed to the contentious relocation plan for U.S. Marine Corps Air Station Futenma.

He was arrested in October on suspicion of cutting barbed wire near the construction site for a U.S. helipad in Higashi, northern Okinawa, and has also been charged with injuring a Japanese Defense Ministry official and obstructing base relocation work at another U.S. Marine base in Nago.

The arrests have sparked an outcry from civic groups and some Diet members from Okinawa who suspect Yamashiro's arrest is aimed at weakening the fierce local opposition to building new U.S. military facilities needed to make the decades-old relocation plan work.

Supporters submitted petitions requesting his release to the Naha District Court last month.

Amnesty International Japan has released a statement calling for Yamashiro's immediate release, saying he does not meet the criteria for being detained because the chances of him destroying evidence concerning his alleged crimes are very low.