The Oregon State Bar has opened an investigation into whether Amanda Marshall committed misconduct while serving as U.S. attorney of Oregon.

Marshall resigned the position last year amid allegations she had an inappropriate relationship with a subordinate - one of her assistant U.S. attorneys.

Earlier this month, the U.S. Department of Justice's Inspector General announced results of an investigation into an unnamed U.S. attorney. Marshall, who is now in private practice in McMinnville, confirmed she was the subject of the investigation.

The federal investigation found Marshall had engaged in a more than yearlong "intimate and personal" relationship with an assistant prosecutor and continued to participate in work matters involving the subordinate. The investigation, announced June 7, also found Marshall violated sexual harassment laws, lied to investigators and tried to block the investigation.

In an emailed statement to The Oregonian/OregonLive, Marshall wrote June 7 that the relationship was the "biggest mistake of my life." Her lawyer also wrote that Marshall initially withheld information to protect her privacy and that of her colleague but later cooperated with investigators.

"By engaging in that affair, I failed the United States Government, my fellow Oregonians, and most of all, my family," Marshall wrote. "I am deeply sorry and will spend the rest of my life trying to make amends."

The state bar's investigation was triggered by an anonymous complaint, which included the summary of the inspector general's inquiry and media reports. Bar investigators received the complaint on June 10 and have given Marshall until July 11 to respond.

If an attorney is found to have committed misconduct, bar officials can apply a broad range of disciplinary actions. An attorney can be publicly reprimanded, suspended - from 30 days to five years - or disbarred. The bar also can offer probationary requirements to allow an attorney to keep their license active or to alter the length of the suspension.

-- Laura Gunderson

503-221-8378; @lgunderson