Oscar-winning actor Gene Hackman and his wife, Betsy Arakawa, had been dead for some time when their bodies were discovered Wednesday during a wellness check at their Santa Fe home, according to investigators. Law enforcement officials have not provided an cause of death for the 95-year-old actor or his 63-year-old wife, as of noon Eastern on Thursday. New details about the discovery of the couple have begun to emerge through a search warrant. Hackman's body was found in a mudroom and Arakawa was found dead in a bathroom next to a space heater. There was an open prescription bottle and pills scattered on the counter top near Arakawa. A dead German shepherd was found in a bathroom closet near Arakawa, police said. Two healthy dogs were found on the property. Investigators have so far found no signs of foul play, gunshot or other wounds, and the New Mexico Gas Co. is working with the Santa Fe County Sheriff’s Department in the investigation, spokesperson Tim Korte told The Associated Press. The involvement of the gas company indicates investigators could suspect carbon monoxide poisoning is to blame for the couple's deaths. Hackman's daughter, Elizabeth Jean Hackman, told TMZ their family believes carbon monoxide poisoning is to blame, but aren't sure. A detective noted that people exposed to gas leaks or carbon monoxide may not show signs of poisoning, but also noted there were no obvious signs of a gas leak.