SACRAMENTO, Calif. — A attorney for an acclaimed Hmong general charged with plotting to overthrow the communist regime in Laos told a federal judge that the talk was nothing more than a “fantasy” egged on by a federal agent who posed as an arms dealer.

General Vang Pao, 77, who was hospitalized last week with chest pains, entered the courtroom yesterday in a wheelchair and sat alongside the 10 other defendants in the jury box. All the men wore orange jumpsuits and shackles.

A prominent San Francisco attorney, John Keker, who has agreed to represent General Vang on a pro bono basis, asked Judge Frank Damrell Jr. to set an unusual two-hour evidentiary hearing and group argument about whether the men pose a danger to the community.

“We would call the undercover ATF agent and ask him about his role in expanding and making much larger what we believe is essentially a fantasy,” Mr. Keker said.

Judge Damrell agreed to take up the dangerousness issue on July 12, though he did not commit to permitting defense attorneys to interrogate the undercover operative.

“This will be our first real opportunity to question the evidence, peel away and see what’s really happened,” a defense lawyer, Mark Reichel, said. He said whatever transpired was motivated solely by a desire to end the suffering of the Hmong in Laos, who have been persecuted for decades. “You have people of extreme good will presented with terrible, ugly, inhumane facts.”

If the judge determines the defendants are not a danger, that would ease the way for some or all of them to be released pending trial. So far, none of the men has been granted bail by federal magistrates who have dealt with the defendants one by one.

As the brief hearing took place, between 2,000 and 3,000 Hmong protesters circled the federal courthouse to demand General Vang’s immediate release.

Some toted signs reading, “Free Our Beloved Father” and “General Vang Pao is an American Hero.”

“We’re here to free Vang Pao,” a postal worker from Sacramento, Ly Yang, 52 said. “He saved a lot of American lives.”

During the Vietnam War, the CIA helped fund and arm the Hmong forces in order to keep pressure on the regime in Laos, which is closely linked to the communist leadership in Vietnam.

“The guy is being framed,” one Vietnam veteran, Kenny Smith, 57, said as he passed by. “The U.S. used to fight against communism. Over time, they decided they don’t care.”