Paramedics were called to the couple's west London home on Monday evening and transported Scoular to a nearby hospital, where she was pronounced dead.
The former Bond girl, 65, had been suffering from bowel cancer, but her cause of death has yet to be determined and her passing is currently under investigation.
A police spokesman confirms: "A post-mortem will be held in due course. Her death is currently being treated as unexplained and officers from Westminster are investigating."
Scoular starred in a variety of British TV programmes, including You Rang, M'Lord, The Avengers and long-running U.K. drama Coronation Street, but she will perhaps be best remembered for her roles in two James Bond films.
She starred as Buttercup in the 1967 original Casino Royale and appeared as Ruby in On Her Majesty's Secret Service in 1969.
Scoular also appeared alongside Marlon Brando and Sophia Loren in A Countess From Hong Kong (1967) and starred with her husband in comedy Doctor In Trouble in 1970.
She wed Phillips, the star of the popular Carry On franchise, in 1982.
In a statement issued on Tuesday (12Apr11), a representative for Phillips, 86, says, "It is with great sadness that we must confirm Leslie Phillips' wife Angela Phillips (nee Scoular) passed away yesterday. The family have requested that their privacy is respected at this difficult time."