The man who fathered kidnapped teen Shawn Hornbeck was a convicted sex offender who did three years in a Missouri prison on drug and sodomy charges, The Post has learned.

The late Walter Hornbeck was 60 when Shawn was born to him and his wife, Pamela Akers. He had little contact with his son, Akers said.

Akers kicked him out of the house when the boy was just 6 months old, and the couple divorced in 1992, about a year after Shawn was born.

Hornbeck was arrested in Washington County, near St. Louis, on Sept. 30, 1992, and charged with rape, although it's unclear who the victim was. Details of the case were not available, and most of the record has been sealed.

But a court official said the reference number on Hornbeck's criminal conviction indicated the charge involved an assault on a minor.

At the time of his arrest, Hornbeck also lived with Shawn's older sisters, Jackie and Jennifer, who were then 7 and 6, respectively.

Hornbeck pleaded guilty to attempted sodomy, a felony, as well as possession of a controlled substance and he was sentenced to seven years in state prison in 1994.

He got out in 1997, when Shawn was 6, but the two had no further contact, said Akers. Hornbeck died July 9, 2000, while on parole.

Pamela married Shawn's stepdad, Craig Akers, in 1999. The couple would not discuss the matter in an interview with The Post.

Shawn's half-brother Ted Hornbeck, who met the freed teen for the first time last Sunday, called their troubled dad "a survivor."

"My father did whatever he had to do to get by," he said.