Gene Hackman and his wife, Betsy Arakawa, tested negative for carbon monoxide poisoning officials said Friday as they continue to investigate what caused the couple's deaths. The pair were found dead at their Santa Fe,

The Santa Fe County Sheriff's Office initially indicated "foul play was not a factor," but investigators quickly reversed that statement, calling the deaths "suspicious" amid an ongoing investigation.

Hackman and his wife, Betsy Arakawa, apparently had been dead for days or even a couple of weeks when investigators found their bodies while searching the couple's Santa Fe home on Wednesday. Investigators are trying to figure out the last time anyone saw or spoke to them, Santa Fe County Sheriff Adan Mendoza told NBC's “Today” show on Friday.