"The Russian woman died at midday (2:00 p.m. Moscow time, 11 a.m. GMT) on Monday in the intensive care unit of our hospital," the official said, refusing to give the woman's name.
Earlier on Monday, police said the woman had been stabbed in the neck in the entrance to an apartment she was renting with her two year-old child. She was renting the apartment from another Russian national.
"Police are looking into the case, and investigators have prohibited the release of information relating to it," a police spokesman said.
A young Spanish man is being sought in connection with the murder.