Over a week after a young scientist died under mysterious circumstances at a Siberian plague institute, the Kremlin has still not publicly identified the germ that killed her.
Russia has not provided a formal answer to the question of how Darya Shipilova, a 28-year-old researcher at the Anti-Plague Institute of Siberia and the Far East, died on October 2.
She was put into a hospital in Shelekhov, a town about 12 miles south-west of Irkutsk, on September 29, where she sadly died just a few days later.
So far, the Kremlin has only said she died from 'pneumonia of unknown aetiology [origin]', without going into any more detail. The World Health Organisation said on Saturday that it still does not know how Darya died.
Worse still, her family are now refusing to discuss her death publicly, amid fears they have been gagged.
Last week, her mother shot down theories that Darya may have been infected after she broke a test tube containing bacteria.
Medical professional Svetlana Shipilova claimed it is 'impossible' to break the test tubes used in these research institutions.
She said: 'I don't want to read nasty things about my child. I know the truth. I find myself fending off foolish acquaintances who actually believed all that.'
Now, Darya's father and brother have refused to speak, local media reported. Little is known about the young scientist's funeral plans either, as there was earlier speculation about whether she would need to be buried in a zinc coffin to prevent the spread of a dangerous infectious disease.
Panic broke out after Darya Shipilova, 28, a lab worker at the Irkutsk Anti-Plague Research Institute in Siberia, reportedly broke a test tube containing live bacteria
Darya's home was disinfected by teams of workers following her death
Darya was involved in testing out antibiotics that fought the Y. pestis bacterium – which causes the plague – according to the New York Times.
On Saturday, the WHO called for a continued investigation into the Siberia incident, adding that it is still seeking to understand the 'causative agent' of Darya's fatal pneumonia.
Russian health officials, it said, had conducted more than 5,500 tests and found no evidence of any dangerous pathogenic microorganisms.
'Additional clinical, epidemiological and laboratory information, including confirmation of the diagnosis in the deceased laboratory worker, is required to improve confidence in the assessment,' WHO said.
The UN health agency has cited initial, unconfirmed reports suggesting pneumonic plague, a severe disease less common than the better-known bubonic plague linked to the Black Death in the Middle Ages.
Pneumonic plague spreads from person to person, causing a severe form of pneumonia, but recovery rates are high if it is detected and treated in time.
Still, it is considered the most deadly of the three main forms of infection due to its ability to spread rapidly.
It is a disease that is endemic to, among other parts of the world, Siberia.
Though plague vaccines have long existed, experts have raised serious questions about how effective and safe they are.
Other issues lie in Russia's handling of the crisis. Though it said it was able to quarantine and test thousands who risked being infected through contact with Darya, officials have said little about the disease.
Rospotrebnadzor, Russia's public health body, has not held any press briefings, instead only providing information through periodic statements.
On top of this, the Kremlin has also declined to take any specific questions regarding the disease, instead urging the Russian people to only listen to public health officials.
Fuelling speculation is the fact that Russia is infamously one of the few countries that continues to work on biological weapons.
Originally set up under the Union of Soviet Socialist Republics (USSR), infectious disease labs were meant to be purely for defence and public health.
But these labs were also closely linked to the USSR's biological weapons programme, which is believed to have continued even after the fall of the Berlin Wall.
An April 2025 US government report on Russia's compliance with international arms control rules indicated that America 'assesses that Russia maintains an offensive biological warfare program and is in violation of its obligations' under the Biological Weapons Convention.