DULUTH (AP) — The Minnesota National Guard says one of the top leaders of the Duluth-based 148th Fighter Wing has been sacked.

The Guard issued a statement Friday saying Col. John H. Spencer Jr. was relieved as vice wing commander Wednesday after an investigation substantiated allegations of “an unprofessional relationship.”

The statement from Guard spokesman Lt. Col. Kevin Olson says the allegations surfaced in July, and were investigated by “an unbiased outside source.”

The Guard isn’t elaborating on what happened. But the Guard says it has “zero tolerance” for unprofessional relationships.

Spencer is on administrative leave pending assignment to another position.