Two American hikers held captive in Iran for nearly two years have a big hitter in their corner: boxing champion Muhammad Ali, the self-proclaimed “greatest of all time.”

Ali on Tuesday led a prominent group of U.S. Muslims in appealing for the release of Shane Bauer and Josh Fattal. The 28-year-old Americans were taken into custody along the Iran-Iraq border in July 2009 and have been held by Iranian authorities ever since.

Bauer’s fianceé, Sarah Shourd, was released on bail last year and returned to the United States.

Like the former heavyweight champion, the two Americans only “wanted to experience the world, they wanted to experience other cultures, they wanted to experience other people,” said Ali’s wife, Lonnie, who spoke on his behalf. The 69-year-old Ali, who has Parkinson’s, sat in a chair next to her, in a dark suit and sunglasses.

The appeal was made a day after the two hikers were allowed to call home for only the third time since their arrest. Bauer and Fattal told their families they had staged a 17-day hunger strike after they were prevented from receiving letters.

Bauer’s mother, Cindy Hickey, of Pine City, Minn., and Fattal’s mother, Laura Fattal, of suburban Philadelphia, joined the call on the Islamic republic’s leaders for action.

A trial had been scheduled to resume May 11, but Bauer and Fattal weren’t brought to court and no explanation was given to the families or their lawyer in Tehran.

Earlier Tuesday, a Foreign Ministry spokesman told Iranian state TV that describing the two as hikers was a “joke.”

The two Americans are charged with espionage. They deny the charges.

“Their detention has everything to do with animosity between Iran and the United States, and nothing to do with anything they have done,” said Shourd, who was released eight months ago on $500,000 bail and has refused to return to Iran for trial. She also was charged with espionage, and has denied the charge. She is being prosecuted in absentia.

The three Americans said they were only hiking in a scenic area of northern Iraq near the Iranian frontier.

-AP