Sergei Magnitsky (8 April 1972 – 16 November 2009) was a Russian accountant and auditor whose arrest and subsequent murder in custody generated international media attention. Magnitsky had alleged there had been a large-scale theft from the Russian state sanctioned and carried out by Russian officials. He was arrested and eventually died in prison seven days before the expiration of the one-year term during which he could be legally held without trial. In total, Magnitsky served 358 days in Moscow's Butyrka pre-trial detention centre. According to reports, he received inadequate health care while in detention. An investigation by the Presidential Human Rights Council found that Sergei Magnitsky had been severely beaten up shortly before he died on 16 November 2009.

As a result of campaigning by Sergei Magnitsky's former employer, Bill Browder, and others, in late 2012 the US Congress and President Obama adopted the Magnitsky Act, formally known as the Russia and Moldova Jackson-Vanik Repeal and Sergei Magnitsky Rule of Law Accountability Act of 2012, a bipartisan bill adopted for the purposes of punishing Russian officials responsible for the death of Sergei Magnitsky 
"On November 16, 2009, after a year enduring inhuman conditions in detention, after his health had completely broken down, after he had spent months in pain and after being denied life-saving medical treatment, Sergei died. On his final days, he experienced such terrible pain that he was put in a so called “medical” isolation ward over the weekend, but with no doctors or equipment. On the morning of Monday November 16th he was so ill and in such excruciating pain that a doctor decided to move him to a to a facility where he could receive emergency medical treatment. However investigators were reluctant to approve the move and they delayed his transfer until 5PM. He was ultimately transferred to another prison where treatment was again withheld. At about 8 pm, the officials, instead of providing medical assistance and saving his life, placed him in a straightjacket and locked him in an isolation cell. One hour and eighteen minutes later, he was dead. This entire time an emergency medical team was stationed outside the door to the cell, but they were not permitted to enter."