WASHINGTON >> Julian Assange, the flamboyant founder of WikiLeaks, is living on a supporter’s 600-acre estate outside London, where he has negotiated $1.7 million in book deals and regularly issues defiant statements about the anti-secrecy group’s plans.

Meanwhile, the young soldier accused of leaking the secret documents that brought WikiLeaks and Assange to fame and notoriety is locked in a tiny cell at the Quantico Marine Corps Base in Virginia. Pfc. Bradley Manning, who turned 23 last month in the military prison, is accused of the biggest leak of classified documents in U.S. history. He awaits trial on charges that could put him in prison for 52 years, according to the Army.

Even as members of Congress denounce both men’s actions as criminal, the Justice Department is still looking for a charge it can press against Assange, demanding from Twitter the account records, credit card numbers and bank account information of several of his associates. Legal experts say there are many obstacles to a prosecution of the WikiLeaks founder, but one approach under consideration is to link the two men in a conspiracy to disclose classified material.

Accusations from supporters that Manning is being mistreated, perhaps to pressure him to testify against Assange, have rallied many on the political left to his defense. The assertions have even drawn the attention of the U.S. special rapporteur on torture, Juan E. Mendez, who said he had submitted a formal inquiry about the soldier’s treatment to the State Department.

Manning’s cause has been taken up by the nation’s best-known leaker of classified secrets, Daniel Ellsberg, who gave the Pentagon Papers to the media in 1971. He denounces Manning’s seven months in custody and media coverage that has emphasized the soldier’s sexual orientation (he is gay) and personal troubles. Ellsberg calls him a courageous patriot.

“I identify with him very much,” Ellsberg said. “He sees the wars in Iraq and Afghanistan, I’d say correctly, as I saw Vietnam — as hopeless ventures that are wrong and involve a great deal of atrocities.”

The military rejects accusations that Manning has been mistreated.

“Poppycock,” said Col. T.V. Johnson, a Quantico spokesman.

He insisted that the conditions of confinement were dictated by brig rules for a pretrial detainee like Manning. The soldier has been designated for “maximum custody” — applied because his escape would pose a national security risk — and placed on “prevention-of-injury watch,” restrictions imposed so that he does not injure himself.

That status is based on the judgment of military medical experts and by the observations of brig guards, Johnson said. Guards check Manning every five minutes but allow him to sleep without interruption from 10 p.m. to 5 a.m., when only dim night lights are on, unless they need to wake him to be certain he is breathing.

Johnson denied that Manning was in solitary confinement, as has been widely claimed, saying that he could talk with guards and with prisoners in nearby cells, although he could not see them. He leaves his 6-by-12-foot cell for a daily hour of exercise, and for showers, phone calls, meetings with his lawyer and weekend visits by friends and relatives, the colonel said.

The prisoner can read and watch television and correspond with people on an approved list. He is not permitted to speak to the media.

“Pfc. Manning is being treated just like every other detainee in the brig,” said an internal military review concluded Dec. 27 and read to a reporter by Johnson. “His treatment is firm, fair and respectful.”

The soldier’s lawyer, David E. Coombs, declined to comment for this article, and two people who have visited him at Quantico — Manning’s aunt, Debra Van Alstyne, and a friend who is an MIT graduate student, David M. House — did not respond to queries.

In an interview with MSNBC last month, House said of his friend that he had “noticed a remarkable decline in his psychological state and his physical well-being.” He said Manning appeared “very weak from a lack of exercise” and that “psychologically, he has difficulty keeping up with some conversational topics.”

In an account on Coombs’ website of his client’s “typical day,” he detailed the restrictions on the soldier but called the guards’ conduct “professional.”

“At no time have they tried to bully, harass or embarrass Pfc. Manning,” he wrote.

Asked why the case appears to be moving so slowly, an Army spokeswoman, Shaunteh Kelly, said the defense had requested a delay in July and that a “706 board,” or mental health evaluation, was not complete.

She added in an e-mail that “Cases involving computers and classified information are very complex and require methodical investigation,” and that all lawyers, members of the 706 board and military investigators needed to get proper clearances.

Assange, with his provocative statements, his recognizable shock of white hair and the charges of sexual misconduct he faces in Sweden, has become WikiLeaks’ public face. But while he began WikiLeaks in 2006, overseeing a steady trickle of revelations, the site drew broad attention for the first time only when it began to release the material that Manning is accused of downloading from his computer in Iraq, where he was a low-level intelligence analyst.

The material includes a video showing two U.S. helicopters shooting at people in Baghdad in 2007, two of them Reuters journalists who were killed; thousands of field reports on the wars in Iraq and Afghanistan; and 251,287 cables sent between U.S. embassies and the State Department.

If Manning was indeed the source of the documents, as he suggested in online chat logs made public by Wired magazine, it is he who is largely responsible for making WikiLeaks a household name and the target of fury from the Pentagon, the State Department and members of Congress of both parties.

He is the only person charged in the WikiLeaks case so far. And despite his supporters’ suspicions that he will be pressured to testify against Assange, the Army spokeswoman, Kelly, said that to date, Manning had not spoken with civilian investigators or prosecutors.

Assange has often spoken highly of the soldier, to whose defense fund WikiLeaks has donated more than $100,000. In an article in the British magazine New Statesman on Thursday that called Manning “the world’s pre-eminent prisoner of conscience,” Assange said he believed the Justice Department’s goal was to force the soldier to confess “that he somehow conspired with me to harm the security of the United States.

”Cracking Bradley Manning is the first step,“ Assange said.

© 2011 The New York Times Company