SAN JUAN, Puerto Rico — A campaign to free a journalist imprisoned at Guantanamo gained support yesterday from the first Muslim member of Congress, who urged authorities to prosecute or release him after more than five years without charges.

Sami al-Haj, a Sudanese cameraman for Al-Jazeera, was captured in 2002 as he tried to enter Afghanistan to cover the war. His lawyer says he denies any connection to terrorism and has been on a hunger strike since January to protest his indefinite confinement. In a rare show of support from an American official, Rep. Keith Ellison, a first-term Democrat from Minnesota, called for a hearing to determine whether the military has legitimate reason to hold Mr. Haj with about 330 other men at the prison on a Navy base in Cuba. “If he’s a bad actor, prove it. If not, let him out,” the congressman told the AP.

Mr. Ellison said he believes all Guantanamo prisoners should be allowed to challenge their confinement in the courts. But he said he is particularly concerned about the detention of a journalist who, as far as he can tell, was “detained for taking pictures.” He made the public statement at the request of Al-Jazeera.

Representatives of Qatar-based Al-Jazeera have been meeting with political and business leaders and media groups in America in recent weeks to draw publicity to Mr. Haj’s detention while simultaneously trying to jump-start American distribution of Al-Jazeera’s English-language channel. “We just want to raise awareness and give support for someone we feel is being totally mistreated,” the network’s head of international media relations, Satnam Matharu, said.

At least two other members of Congress have expressed concern about the cameraman but were not yet ready to make a public statement, Mr. Matharu said.

As part of its campaign, the network plans a series of new video spots for its Arabic and English language channels and will revamp an Internet site devoted to the campaign to free Mr. Haj. “We’re standing behind him and we vouch for his innocence,” he said.

At a military hearing that determined Mr. Haj, 38, was an “enemy combatant,” American authorities accused him of transporting money in the 1990s for a charity that provided funding to Chechen rebels, and of having other links to Islamic militants. But the military has never disclosed in detail why he was captured on the Afghanistan-Pakistan border and turned over to America.

The American military says the Guantanamo detainees are held on suspicion of terrorism or links to Al Qaeda or the Taliban. Mr. Haj is believed to be the only journalist from a major news organization imprisoned at the base.

“Mr. al-Haj’s detention is in no way based on his status as a reporter or the content of his reporting,” Navy Commander Jeffrey Gordon, a Pentagon spokesman said. “There is a significant amount of information, both classified and unclassified, which supports detention of enemy combatants by U.S. forces.”

Mr. Gordon noted that Mr. Haj’s detention is reviewed at an annual military hearing, and that he can challenge his “enemy combatant” status in the courts. However, Congress and President Bush have limited federal court challenges to a review of military procedures, and stripped Guantanamo detainees of the broader right to challenge their confinement through habeas corpus petitions. The Supreme Court is reviewing that action in its current term.

Mr. Ellison, who supports restoring habeas rights to detainees, said he has conducted research into the case and has not seen anything solid linking Mr. Haj to any crimes.