Unnamed spouse flicked through her other children's diaries and found claims Katie Pladl was pregnant and Steven Pladl was the dad.
A wife was shocked on learning that her husband was having an incestuous affair with his own daughter when she read the child’s diary.
Steven Pladl, 42, of Wake County, North Carolina, left his wife to start a relationship with Katie Pladl, 20 - and even fathered her child.
The wife, discovered the terrible truth when she went through her other children’s journals and found that Katie was pregnant, with her dad’s child.
When confronted, he told his wife about the affair and moved 150 miles with his daughter to Knightdale, North Carolina.
The couple gave up Katie Pladl for adoption as a baby but she contacted her parents through social media when she turned 18, police said.
She went to live with her biological parents and their two children near Richmond, Virginia, in August 2016 before the couple legally separated three months later, according to WNCN.
According to his wife, her husband would sleep on the floor of Katie's room in the months before she moved out.
Steven told his other children to call their eldest sibling their 'step mom', according to the police report.
In November last year a warrant was issued for their arrest.
They were located at an address last week, where officers discovered a baby boy who is understood to be four-months-old.
Steve and Katie Pladl were held at the Wake County Detention Center pending extradition to Virginia and charged with incest with adult, adultery, contributing to delinquency.