The singer split from Andy Willner in 2009 after seven years of marriage. Their divorce was finalised the following year.
The couple adopted children Zac and Magdalena in 2008.
She told the Daily Mail: "The truth is even now I don't know why he divorced me. Perhaps you had better ask him.
"He has never really explained to me why he went back to Hong Kong [from London] and the truth is that it still hurts.
"There was a lot of bitterness at first, as there is after divorce. We didn't talk for a year, but we were friends before we married and we are once again friends."
Sinitta previously insisted that her close friendship with ex Simon Cowell did not contribute to the divorce.