MOSCOW - The only official charged with the death of a Russian whistle-blowing lawyer walked free on Friday after a Moscow court acquitted him of negligence, in a case that has become a rallying point for human-rights advocates and sparked escalating legislation in the United States and Russia.

Sergei Magnitsky died in jail in 2009 after his pancreatitis went untreated, and an investigation by Russia's presidential council on human rights concluded he was severely beaten and denied medical treatment. Prison doctor Dmitry Kratov was the only person to face trial in the case.

Judge Tatyana Neverova said she found no evidence that Kratov's negligence could have caused the lawyer's death. The acquittal was widely expected after prosecutors this week dropped their accusations, saying they had decided there was no connection between Kratov's actions and Magnitsky's death.

The case has angered both Russian activists and the West. The U.S. Congress passed legislation this month in Magnitsky's name, calling for sanctions against officials - including Kratov - deemed to be connected with human-rights abuses. The bill provoked retaliation from Moscow, including a measure barring Americans from adopting Russian children that President Vladimir V. Putin signed on Friday.

Magnitsky, a lawyer for the Hermitage Capital fund, was arrested in 2008 on suspicion of tax evasion by the same Interior Ministry officials he accused of using false tax documents to steal $230 million from the state. He died while in custody awaiting trial.

Government officials have dismissed calls to investigate police officials and the only official charged in his death was Kratov, who was deputy chief physician at the Butyrskaya prison where Magnitsky was held.

Hermitage's owner, Bill Browder, said the outcome of the trial shows the government's unwillingness to find to try the culprits.

Kratov pleaded not guilty to charges of negligence leading to death, saying he was unable to ensure medical care for Magnitsky because of a shortage of staff.