Any Russian police officers found guilty of involvement in the death of lawyer Sergei Magnitsky will face severe punishment, Interior Minister Rashid Nurgaliyev said on Tuesday.
"If something is proved, there is no question about that - I will burn them out with red hot irons," he said.
"However, in this case there has been no decision yet - we cannot bring anything against them," the minister said.
Nurgaliyev was responding to a reporters' question as to why the records of police officers accused by rights activists of involvement in Magnitsky's death were approved in a recent performance review.
Magnitsky's mother is to meet with an investigator later in the day for an interview. Magnitsky's wife was interviewed earlier.
The Interior Ministry previously said that the future of the case would depend on Magnitsky relatives. It will either be dropped or go to court.
Two doctors were charged over Magnitsky's death earlier this month. A Kremlin rights council said the death of the Hermitage Capital lawyer was likely to have resulted from a beating in jail and the failure of prison doctors to provide timely medical assistance to him.
Magnitsky died in November 2009 after almost a year in Moscow's notorious Matrosskaya Tishina pretrial detention center. He was detained on tax evasion charges shortly after announcing he had uncovered massive fraud by police investigators.
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."