Michael Lohan is the father of yet another child.

Lindsay's dad, who is currently expecting a baby with Kate Major, appeared on The Trisha Goddard Show where a DNA test confirmed that Papa Lohan is the dad to 17-year-old Ashley ... an illegitimate lovechild with Kristi Horn.

Until now, Lohan has denied that he is the father and has refused to pay child support.

Michael is also the father to sons Michael Jr., Cody and daughter Ali ... his kids with ex Dina Lohan.

Lindsay has yet to comment on the news that Ashley is her half-sister.