Ashley Horn - Michael Lohan's Secret Daughter?

Ashley Horn (aka Ashley Kaufmann) might really be a Lohan!

Life & Style has obtained the birth certificate of Ashley Horn, the 15-yr-old who claims to be the secret daughter of Michael Lohan - and half-sister of Lindsay Lohan.

Ashley birth certificate names Michael Lohan as her father!

Ashley's mother, Kristi Kaufmann had a brief affair with Michael in the early 1990's while he was married to but separated from Dina Lohan. The mother-daughter came forward with their story in 2008, but Michael denied that he was the father.

"In December 2008 we had a court hearing that Michael was ordered to appear at for the DNA testing," Kristi tells L & S. When Michael didn't show, a judge ruled that his name could be added to the birth certificate.

Despite having his name on the legal document, Michael is still denying that he's Ashley's father, "I'd be glad to take a DNA test!" Michael said recently.

Kristi also claims Michael owes $300,000 in child support.

Even though Kristi has been trying to tell the world that Ashley is Michael Lohan's daughter, the teen has no desire to see her "dad."

"I do not trust him, and I don't want to be around him or part of his life," Ashley says. "I could never call Michael Lohan 'Dad.' A dad is a person who is there for you and takes care of you."

Photos of Ashley Horn below: