Betsy Arakawa, the concert pianist who was married to actor Gene Hackman, died from hantavirus pulmonary syndrome, according to an autopsy report that said that her lungs were heavy and congested.

Arakawa, 65, had fluid accumulation in her chest and mild hardening of the vessels that supplied blood to the heart and body, according to the autopsy reports on Tuesday (Wednesday AEST).

Hantavirus is a rare but potentially fatal disease spread by infected rodent droppings.

Arakawa tested negative for COVID-19 and the flu and showed no signs of trauma, the autopsy report said. Her carbon monoxide levels were within normal range, and she tested positive for caffeine and negative for alcohol and intoxicating drugs.

Arakawa’s autopsy and toxicology reports were released two days after similar documents on Hackman’s death were made public, confirming his main cause of death was heart disease.

The 95-year-old actor also was in the advanced stages of Alzheimer’s disease and likely had not eaten for a long time, according to his autopsy. He tested negative for hantavirus.

Records released earlier in the investigation showed Arakawa made phone calls and internet searches as she scoured for information on flu-like symptoms and breathing techniques.

Recently released videos outline the scope of the investigation into the deaths of Hackman and Arakawa.

Before they understood how Hackman and Arakawa died, authorities recorded themselves conducting interviews with workers and returning to Hackman’s home to search for more evidence.

Detectives searched the home in early March for Arakawa’s laptop and other clues.