Despite Michael Lohan's reported denial that he fathered a child out of wedlock, his daughter Lindsay Lohan said on her MySpace blog that she knows she has a half sister, along with her other younger siblings. She also said her half sister probably is about the same age Aliana, her younger sister.

'In Touch' reports that Lohan's half-sister may be Ashley Kaufmann of Montana, daughter of massage therapist, Kristi Kaufmann. Michael Lohan has admitted he had a fling with Kristi Kaufmann in 1995, during his separation from Dina Lohan, mother of Lindsay's mom.

In a post titled "Random Thoughts", the 22-year-old Lindsay wrote: "My father just let my family and me know, amongst other things that he had another child after my little sister Aliana. Or maybe he had it before Aliana?? Either way, he cheated on my mother, and that really sucks."

However, Michael Lohan, who reportedly took a paternity test in July, said there is a "99 percent chance" that the MySpace message on Lohan's blog was actually written by her girlfriend, Samantha Ronson.