The singer's sister La Toya Jackson confirmed: "Vitiligo is on my father's side and Prince has it, too - on his arms and chest."
Both dermatologist Arnold Klein and Oliver! star Mark Lester have revealed they donated sperm samples and could be his father.
But this latest revelation appears to suggest that Jacko was his dad after all as he suffered from the hereditary condition which affects skin pigmentation.
La Toya also revealed that Prince, along with Jacko's other children Paris, 11, and Blanket, seven, have been seeing a psychiatrist to help them deal with their grief.
"Paris' bedroom is covered with posters of her father, Prince doesn't want to speak about it and Blanket is just very sad - he cries," she told new! (must ref)
"They're working with a psychiatrist. You have to have someone to ask how you're feeling and go through the hurt with."