Insiders claim Donte Williams Jackson, who lives with the late `Thriller` star`s 80-year-old mother Katherine Jackson, is the result of a fling between the legendary King of Pop and an unknown woman.
The 18 year old has spent most of his life being looked after by Alejandra Oaziaza, who has four children with Michael`s brothers Randy and Jermaine.
It was initially believed Donte was the son of Randy and Alejandra, but he was born just eight months after their son Randy Jr.
A source told The Sun newspaper: "Michael was very close to Donte. We`re not even sure if Donte knows who his parents are.
"He`s one of the nicest kids you could possibly meet."
Insiders claim Donte came about after a fling in Las Vegas in the early 1990s.
Donte is the second allegedsecret son of the legendary singer, who has children Prince Michael, 13, and Paris, 12, with ex-wife Debbie Rowe and eight-year-old Prince Michael II, also known as Blanket, whose mother is unknown.
It is also believed 26-year-old dancer Omer Bhatti is his child.