WASHINGTON — The Supreme Court ruled today that federal officials can indefinitely hold inmates considered "sexually dangerous" after their prison terms are complete.

The high court reversed a lower court decision that said Congress overstepped its authority in allowing indefinite detentions of considered "sexually dangerous."

"The statute is a 'necessary and proper' means of exercising the federal authority that permits Congress to create federal criminal laws, to punish their violation, to imprison violators, to provide appropriately for those imprisoned and to maintain the security of those who are not imprisoned by who may be affected by the federal imprisonment of others," said Justice Stephen Breyer, writing the majority opinion.

President George W. Bush in 2006 signed the Adam Walsh Child Protection and Safety Act, which authorized the civil commitment of sexually dangerous federal inmates.

The act, named after the son of "America's Most Wanted" television host John Walsh, was challenged by four men who served prison terms ranging from three to eight years for possession of child pornography or sexual abuse of a minor. Their confinement was supposed to end more than two years ago, but prison officials said there would be a risk of sexually violent conduct or child molestation if they were released.