MINNEAPOLIS (AP) — A man who authorities say is a person of interest in the 1989 abduction of Jacob Wetterling has pleaded not guilty to several federal child pornography charges.

Fifty-two-year-old Danny Heinrich appeared in U.S. District Court in Minneapolis on Monday. He was indicted last year on 25 counts of possessing and receiving child pornography.

Court documents say investigators found the suspected child porn in numerous three-ring binders located throughout his Annandale home during a search last July and recovered additional images from his computer's hard drive. Authorities say they found the images while investigating the disappearance of Jacob, who was 11 when he was kidnapped near his home in St. Joseph.

Authorities have not charged Heinrich in Jacob's abduction, and Heinrich has denied any involvement.