Nicole Falkingham's death has been attributed to hypothermia and possible alcohol poisoning, the Liverpool Daily Post reported Monday. She was 41.
Police said Falkingham's body was discovered Friday morning in a car parked outside the couple's home in the suburban Otterspool neighborhood in Liverpool.
A search of their property also turned up 100 marijuana plants, police said, and they have also been charged with their possession.
Investigators said the couple and Falkingham were at the Vinci Bar in Liverpool for several hours, leaving at about 9 p.m. Thursday. Police have appealed for anyone who saw her in the hours before her death to come forward.
Falkingham's estranged husband, Jonathan, is chief executive of the development company Urban Splash and described as a millionaire. He changed his Facebook status to single on New Year's Eve, the Post said.