Europe's top human rights court rebuked Russia on Tuesday for multiple violations of the basic rights of lawyer Sergei Magnitsky who died in a Moscow prison in 2009 after complaining of mistreatment.

Magnitsky, whose death became a cause celebre, received inadequate medical care in custody which led to his death, was ill-treated by prison guards and was held in over-crowded conditions, the European Court of Human Rights ruled.

The court said the subsequent investigation into his death had been lacking, and ordered Russia to pay out $38,000 to Magnitsky's widow and mother who took up his case at the court in Strasbourg after he died.

The court rejected a complaint calling his arrest and detention ill-founded and said that authorities had reasonable grounds to suspect him of being involved in tax evasion.