Alexei Pichugin had appealed his sentence, hoping for acquittal. Kamil Kashayev, the attorney for the prosecution, said a life sentence was appropriate as the defendant's crimes had put many people at risk.
Last year, Pichugin was indicted for a series of murders believed to have been committed at the behest of his bosses at the now bankrupt oil company, after pleading not guilty, and was sentenced to 20 and later to 24 years, despite previous calls for a life sentence from the prosecution.
Both sides appealed, and the Moscow City Court ordered a new trial, which is currently in progress.
Pichugin's defense lawyer Ksenia Kostromina said the European Court of Human Rights had raised concerns with the Russian government over observance of criminal procedures in her client's case.
She said the list of issues arousing concern in Strasbourg included the lack of availability of medical assistance, the extension of her client's arrest during police inquiries, and the dubious legality of the judges' appointment procedure and their decision to keep the trial closed to the public.
