Washington ? Senate Finance Committee Chairman Max Baucus defended recommending his girlfriend for appointment as Montana’s U.S. attorney, saying Saturday his one-time staff member and the former state prosecutor is “highly qualified” but eventually withdrew her nomination.

Baucus said that he began dating former state office director Melodee Hanes after they were both separated from their spouses. The Montana Democrat said they did not have an affair, but began dating while she worked for him.

Republican National Committee Chairman Michael Steele called Saturday for a Senate Ethics Committee investigation of Baucus’ actions. Steele said the panel should determine “why Senator Baucus put his personal needs above those of the people of Montana.”

Baucus, who is helping lead Democratic efforts to expand health care, recommended Hanes for the federal prosecutor job in February. The senator said he appointed an independent, third-party reviewer and established “an open and fair process” that resulted in her name and two others being sent, unranked, to the White House for consideration.