Moscow, April 28 (IANS/RIA Novosti): The death of lawyer Sergei Magnitsky in a Moscow pre-trial detention facility was a "tragedy" Russian President Vladimir Putin said Saturday while insisting no crime had been committed.

Magnitsky was detained in November 2008 after alleging a $230 million tax-embezzlement scheme by Russian officials and died less than a year later in a pre-trial detention centre.

"Investigation bodies came to the conclusion that there was no ill intention, no criminal negligence," Putin said in an interview with the state-run Rossiya-1 TV channel. "A tragedy occurred."

"There was no torture," Putin said. "There was nothing that would demand any criminal charges being brought."

Magnitsky’s death sparked tensions between Russia and the US, which late last year introduced sanctions against Russian officials accused of human rights violations.

Just weeks after the law was enacted, Russia banned US nationals from adopting Russian children.

Magnitsky’s former boss, William Browder, the head of equity fund Hermitage Capital, has alleged the Muscovite lawyer was killed in revenge for uncovering the purported embezzlement scheme.

Investigators initially said the 37-year-old lawyer had died of “heart failure,” but in 2011 the Kremlin’s human rights council said there were “grounds to suspect that Magnitsky’s death was the result of a beating” and the denial of medical assistance.

Late last year, however, Putin reverted to the heart-failure explanation in a nationally broadcast press conference, seemingly dismissing the findings of his ombudsmen.

Two prison officials were investigated in connection with Magnitsky’s death, but one was acquitted and the other not charged.