Whitney Houston -- Family 'Disgusted' by Casket Photo

Whitney Houston's family had "their heart broken all over again" this week when they saw a photo of Whitney laying in her casket published on the cover of a magazine ... TMZ has learned.

Sources close to the family tell TMZ the family is disgusted the photo was printed and they have no idea how security surrounding the casket was breached. We're told the family could tell from the photo that it was taken from inside the funeral home, but they have no idea who would have snapped the pic.

Our sources say Whitney's mother, Cissy, has taken the publication of the photo the hardest.

Despite their disgust and outrage, we're told the family will not investigate the matter further.