Just under two months after actor Gene Hackman and his wife Betsy Arakawa were discovered deceased in their Santa Fe residence, public health authorities announced this week that the extremely rare virus that claimed Arakawa's life has also been connected to the deaths of three additional individuals.

The Oscar-winning actor and classical pianist were found in separate rooms back in February, with a coroner determining that the couple had been deceased for 'some time'. The body of one of their dogs was also found within the property.

Initially, investigating officers deemed the triple death as 'suspicious enough' to warrant further investigation, which eventually led the chief medical examiner to uncover the cause of Hackman and Arakawa's deaths.

Dr. Heather Jarrell later informed the press that the 95-year-old Hackman had passed away from atherosclerotic cardiovascular disease, with Alzheimer's disease being a significant contributing factor.

It was determined that Hackman had died approximately a week after Arakawa, 65, who succumbed to a more complicated condition.

The pair died of different causes (Donaldson Collection/Michael Ochs Archives/Getty Images)

The musician suffered from Hantavirus pulmonary syndrome.

According to the Centers for Disease Control and Prevention (CDC), Hantavirus is primarily spread by rodents - not from person-to-person - if someone comes into contact with the animals' urine, droppings, or saliva.

Transmission can also occur through a rat bite or scratch, although this is considered rare.

Hantavirus pulmonary syndrome is clinically characterized by flu-like symptoms, such as fever, muscle aches, cough, vomiting, and diarrhea, potentially leading to shortness of breath, cardiac or heart failure, and lung failure.

In California, officials have reported that an additional three residents from Mammoth Lakes have since died from the rat-borne condition, as per a statement released to the press last Thursday (3 April).

The warning described the new figures as 'tragic' and 'alarming'.

Arakawa died of Hantavirus (Michael Macor/San Francisco Chronicle via Getty Images)

Dr. Tom Boo, a county public health officer, stated: "The occurrence of three cases in a short period is concerning, especially this early in the year."

He added that officials have yet to determine how the third and latest victim contracted the virus.

Boo continued: "The home showed no signs of mouse activity. We noticed some mice in the workplace, which is not uncommon for indoor spaces at this time of year in Mammoth Lakes.

"We haven’t identified any other activities in the weeks leading up to the illness that would have increased this person’s exposure to mice or their droppings."

The medic added that the population of deer mice in California's Eastern Sierra region is believed to be at an all-time high - according to NBC News - which could be heightening exposure risks.

An official health warning has been issued (Vishal Bhatnagar/NurPhoto via Getty Images)

Boo further disclosed that there is no indication that the three victims since Arakawa's death were involved in activities that would have placed them near common hantavirus exposure zones.

The doctor emphasized that US residents should be more cautious about the potential presence of mice and rats in their homes.

"We’ve now gone about a month without any additional suspected cases, but remain concerned about the increase in activity," Boo concluded.