Sergei Magnitsky was just one statistic among more than 4,000 people who die each year after being consigned to Russia's overcrowded and brutality-plagued prison system.

But the story of the dedicated corporate lawyer who died under suspicious circumstances in pretrial custody two years ago, after being arrested by the very police officers he had testified against in a major corruption case, has shocked the world and led to a wave of repercussions that could undo the tenuous "reset" that has thawed US-Russian relations since President Obama took office.

The US Senate is considering a bill that would impose visa restrictions and financial penalties on 60 Russians allegedly involved in Mr. Magnitsky's imprisonment and death, while the State Department has already put less sweeping measures in place. Russia has retaliated with its own list of 11 US citizens, mainly associated with the detention center at Guantánamo Bay, who may not enter Russia.

But as US and Russian officials ratchet up their rhetoric and exchange cold-war-style blacklists, many who are closely involved with the case say they don't want to see it become a new source of division, but rather hope for an outcome that establishes new standards of international accountability.

"This is not an anti-Russian campaign by any means," says Bill Browder, founder of Hermitage Capital, once Russia's largest investment fund, for whom Magnitsky was working at the time of his 2008 arrest.

Backlash already

The controversy may already be taking a toll at the nuts-and-bolts level of US-Russia relations.

Two Russian generals of the Interior Ministry, which oversees police and internal troops, have reportedly called off plans to attend a conference on intellectual property rights in Washington next week after two senators, Roger Wicker (R) of Mississippi and Benjamin Cardin (D) Maryland, urged the State Department to review their visa applications. The senators allege the two officers, Gen. Maj. Tatiana Gerasimova and Gen. Maj. Nikolai Shelepanov, were involved in the Interior Ministry's coverup of what happened to Magnitsky.

News agencies quoted The Coalition for Intellectual Property Rights, which organized the conference together with the US Justice Department, as saying it "had no indication that any of these officials were involved in the Magnitsky matter."

Mr. Browder's intense international lobbying efforts, aimed at forcing the Russian government to bring Magnitsky's alleged killers to justice, have been the driving force behind the sanctions announced in the United States, as well as a bill currently before the Canadian Parliament, and measures at various stages of development in several European countries.

Browder, once an active player in Russian financial circles and an early supporter of then-President Vladimir Putin, left the country in late 2005 and has since been banned from the country on "national security" grounds.

"This is an anti-impunity campaign to target the money and travel privileges of corrupt officials for the benefit of honest Russians," he says. "We have huge support among the Russian people for what we are doing."

As a lawyer working for Hermitage, Magnitsky uncovered what he later testified was a vast scam by top police officials to embezzle $230 million that Hermitage Fund companies had paid in corporate taxes in 2006. According to him, the corrupt cops used corporate seals and documents seized in a June 2007 raid on Hermitage's Moscow office to set up fake companies under the same names, which then applied for and received a full tax rebate.

Browder believes the scheme to defraud the state treasury of nearly a quarter of a billion dollars must have involved a wide range of conspirators, including tax officials and high-level government figures.

Magnitsky appeared twice before the State Investigative Committee in 2008, where he described in detail how the theft had been carried out and named several police officials. The Interior Ministry, which oversees the police, subsequently assigned those same officers to investigate Magnitsky's claims and, in November 2008, they arrested him and charged him, ironically, with tax evasion.

A year later, Magnitsky was dead. According to a report issued last summer by a commission of human rights experts working under President Dmitry Medvedev, he had been systematically deprived of medical treatment, kept in appalling conditions, and denied access to his family.

Brutal quest for confession of guilt

On the night he died, prison officials kept an ambulance waiting for an hour while eight guards took Magnitsky into a holding cell in handcuffs as prison doctors stood by, says Valery Borshchev, a member of the Kremlin human rights council.

"It has been established that he was beaten, even though he was in a critical state of health, in an effort to make him sign a confession of guilt," says Mr. Borshchev. "I don't think they meant to kill him, but taken all together, it led to his death."

The Interior Ministry has rejected the findings of the Kremlin human rights council, even though Mr. Medvedev appeared to endorse them last July, saying "[Magnitsky] is gone, and to all appearance, indeed some crimes were committed leading at least to this result."

The State Investigative Committee has extended its inquiry eight times, and is slated to report on Nov. 24.

"I have little hope that we will ever see this case investigated properly," says Borshchev. "Nobody [at the top] wants the real reasons it happened to be revealed."

Last month two doctors were indicted on charges of negligence, and they may go to trial. But Browder says the doctors are small fish. "These doctors are clearly guilty of the more serious crime of torture by deliberately withholding medical care from a gravely ill man, but that is not being addressed in the case against them," he says.

Out of 60 people, including high officials, who have been identified as involved, "58 have been fully exonerated," Browder says. "Only these two lowest-level people ... are being charged. They are clearly scapegoats."

Many Russian human rights veterans say that, despite the risk of worsening East-West relations, pressuring the government through international sanctions may be the only way to bring about justice in such cases.

"There are lots of miscarriages of justice in the Russian system, and no one ever answers for them, but Magnitsky was the employee of a prestigious foreign firm and many people worked to bring his story into the light," says Oleg Orlov, chairman of Memorial, Russia's largest human rights organization. "So, this kind of pressure, even if it gets denounced as 'interference into Russia's internal affairs,' is actually good for Russian citizens," he adds. "The case has become a lever that gives rise to real hopes that the system can be changed."

Browder echoes that sentiment in laying out the objectives of his campaign. The first is specific justice for Magnitsky, whose death hit Browder "like a knife through my heart."

The second, more important goal: "making sure that Sergei's death wasn't a meaningless death, but something that has changed Russia for the better."