DULUTH — Sheriff’s officials in northeastern Minnesota say an aerial and ground search for a missing 7-year-old boy have failed to turn up any new leads on his disappearance. Authorities believe Wyatt Nordrum is with his father, who lost custody of the boy.

The Minnesota Department of Natural Resources helped local official check property owned by the boy’s father and grandfather in St. Louis County and Carlton County.

A warrant has been issued for the arrest of James Nordrum Jr. He failed to return the boy to authorities on March 27. Investigators haven’t traced any cell phone or credit card activity to Nordrum and don’t even know what vehicle he may be driving.