Police were called to Brown Jr’s home in Encino, Los Angeles, on Wednesday 18 November in response to a “medical emergency”.
The cause of death has not yet been disclosed, but TMZ reports that the singer’s son was experiencing “flu-like symptoms” in the days before his death.
In a statement released to TMZ, Brown asked fans to “keep my family in your prayers at this time”.
“Losing my son at this point in our lives has devastated my family. There are no words to explain the pain,” he said.
Brown Jr’s brother, Landon, had earlier shared a black-and-white photo of him on Instagram, adding the caption: “I love you forever king.”
Brown Jr’s death comes after that of his half-sister, Bobbi Kristina, who died in 2015. Her mother, Whitney Houston, died after accidentally drowning in a bath in 2012.
Bobby Brown, known for hits including “My Prerogative”, has five surviving children.