The U.S. Supreme Court has refused to review the case of a German man who says he was kidnapped and tortured by CIA agents.

The court did not give its reasons for dismissing the suit, but lower courts have ruled that letting Khaled el-Masri's case go to trial would reveal state secrets.

El-Masri, a German citizen of Lebanese descent, says he was kidnapped by CIA agents in Macedonia in 2003 and flown to Afghanistan.  He says he was held for months on suspicion of terrorism and tortured by his interrogators, freed only when U.S. officials determined they seized the wrong man.

The United States acknowledges what it says is the legal "extraordinary rendition" of terror suspects, but denies that it engages in torture or allows prisoners to be tortured by others.

Earlier this year Germany tried to extradite 13 suspected CIA agents to stand trial in the el-Masri case.  The justice ministry in Berlin had to drop its efforts after the U.S. refused its request that the suspects go to Germany for trial.

Many U.S. allies have condemned Washington's practice of arresting terror suspects and flying them to third countries for questioning.

Human rights groups say they are concerned that some prisoners are tortured.

Some information for this report was provided by AFP, AP and Reuters.