A Spanish police officer added: “We are still awaiting autopsy results but everything at this stage is pointing towards her death being the result of natural causes.”
The Liverpoon-born star enjoyed her first taste of fame at the city's Cavern Club, where she performed alongside acts including The Beatles and Gerry and the Pacemakers.
Cilla relaxes at the Liverpool music venue the Cavern Club Picture: John Pratt
She went on to release 14 albums but later established herself as a television personality, presenting hit shows including Surprise Surprise and Blind Date.
In 1968, she became the first woman to have her own prime-time chat show on BBC One.
In more recent years, despite suffering from arthritis and deafness, she remained in the public eye. Her rise to stardom was recently told in award-winning three-part drama, Cilla, starring Sheridan Smith.
With her husband Bobby Willis taking their first son, 10-day old Robert John home in 1970 Picture: Rex
Most of the shutters were down at the entertainer’s house near Marbella on Sunday morning and there was no answer on the door.
However, a light outside the property was on, a grey Seat Ibiza car was parked outside and the back patio doors appeared to be open.
Police sources said they thought the death had occurred overnight and they believed Cilla, who suffered from hearing problems and arthritis, had jetted to Spain a few days ago with one of her three sons
Cilla Black receives MBE at Buckingham Palace Picture: Rex