Oksana Grigorieva says she was as shocked as the next guy after learning that her key confidante and bodyguard was a twice over felon with a history of impersonating a cop with guns ... this according to her interview with People.
Oksana told the reporter this about Kristian Otto Herzog: "He was somebody that was supportive of me. I didn't know anything about [his record]. I'm withdrawing any communication with him."
TMZ broke the story, Herzog got out of jail several months ago after serving 255 days for impersonating a cop with a loaded gun.
Judge Scott Gordon issued a restraining order against Herzog Monday, prohibiting him from going near Lucia.
As TMZ first reported ... before seeking the restraining order Mel's people contacted Oksana and explained their concerns about Herzog, but she refused to take action.