Relatives of the late lawyer Sergei Magnitsky have requested that the tax evasion case against him prior to his death in a pre-trial detention center be dropped.
Magnitsky's mother, Natalya, said the decision to reopen the tax evasion case was immoral since her son's persecution was being carried under the guise of clearing him of charges.
In early August, investigators reopened the case after the Russian Constitutional Court had ruled that the death of a defendant must not lead to the closure of an investigation.
Magnitsky died after almost a year in a notorious Moscow pre-trial detention center in November 2009. He had been arrested on tax evasion charges just days after claiming that police investigators had stolen $230 million from the state.
A Kremlin human rights council report said in July that Magnitsky's death was likely to have been the result of a beating and that the charges against him were fraudulent. Human rights activists and his former colleagues allege the officers he had accused were involved in his death, which was originally said to have been the result of "heart failure" at the age of 37.
The Interior Ministry previously said that the future of the case would depend on Magnitsky's relatives to be either dropped or go further through the court system.
"We are against the resumption of the investigation," Dmitry Kharitonov, the lawyer of Magnitsky's wife said.
Magnitsky's mother, who was scheduled to be questioned by investigators on Tuesday, refused to give any testimony.
"I openly declare that I am afraid of these investigators. It's not just I don't trust them, I'm afraid of them...I ask for protection for myself and all of Sergei's closest relatives from persecution from the investigators involved in my son's death," Natalya Magnitsky said in a letter to Russia's chief prosecutor, Viktor Chaika.
The United States has recently imposed visa bans on at least 60 Russian officials allegedly involved in Magnitsky's death.