Former Spice Girl Emma Bunton made an emotional plea and offered a reward for the safe return of her "beloved" chocolate brown Labrador after the dog went missing.
Phoebe, described as a "gentle" dog who is microchipped, went missing on Monday during a walk on Hadley Wood Common in north London.
Bunton has appealed to her Twitter followers for help finding her pet and said she was "in bits" after the dog's disappearance.
The singer and Heart FM Breakfast Show presenter has teamed up with DogLost, a free service which aims to help reunite missing dogs with their owners, and has offered a reward for Phoebe's safe return.
Anyone with any information is urged to call 07976 906273.