The widow of late Russian dissident Alexey Navalny said on Thursday that investigators had told her his death in an Arctic prison colony in February was caused by a "combination of diseases" - a finding she rejected as preposterous.
Yulia Navalnaya said she would demand a criminal investigation of her husband's death, which she considers to be murder, and that Navalny's team would continue to conduct its own probe.
Navalny, 47, died suddenly on Feb. 16, depriving the Russian opposition of its most charismatic and popular leader. He had been serving sentences totalling more than 30 years on charges he said were rigged in order to silence his criticism of President Vladimir Putin.
The Kremlin has strongly rejected his supporters' accusation that Putin had him murdered.
Posting on social media, Yulia Navalnaya published a copy of a three-page official letter she received last week stating there were no criminal circumstances surrounding her husband's death and therefore no grounds to open an investigation.
The letter was signed by Alexander Varapayev, the same investigative official who, according to Navalnaya, initially refused to hand over her husband's body to his mother unless she agreed to have him buried in secret - a demand she rejected.
The letter said Navalny had fallen ill suddenly while walking in a prison yard, and was taken to a medical unit where staff tried unsuccessfully to save him with "indirect heart massage and artificial respiration." An emergency team was sent for, but was also unable to revive him.
Navalnaya said that version was a lie and a cover-up.
"We know very well that when Alexei became ill, he was taken not to the medical unit, but back to the punishment cell. That he was dying there, alone. That he was taken to the medical unit already unconscious. That in the last minutes before his death he complained of acute pain in his stomach. Why is all this not in the resolution of the Investigative Committee?" she wrote.
She did not say how she and her husband's supporters had established the sequence of events she described.
The official letter said the cause of Navalny's death was a "combination of diseases" which it presented as a long list, ranging from hypertension and pancreatitis to damage to his vertebrae and the presence of herpes virus in his lungs and spleen.
It said the trigger for his death was a critical increase in blood pressure that had upset the rhythm of his heart and overloaded the pressure in its chambers.
Navalnaya said "every third person in Russia" had chronic diseases of the kind listed by the report, and "people don't die suddenly from something like that in the space of an hour." She also challenged the diagnosis of heart arrhythmia.
"Tell me, how did you discover this arrhythmia during the autopsy? Heart rhythm disturbances cannot be determined posthumously, and during his lifetime Alexei did not have any heart diseases," she said.
She said Navalny had been lively and cheerful when he appeared by video link at a court hearing on the eve of his death. And if he had really been suffering from so many diseases, she demanded, then "why was such a sick person sent to a punishment cell and kept there for months?"
Navalnaya demanded the opening of a criminal case, though she said there would be no investigation as long as Putin remained in power.
"Therefore, we will continue to investigate ourselves," she wrote, urging prison staff and officials to contact her team confidentially and promising to pay for any new information.
