"The OCE reviews allegations of misconduct against Members, officers, and staff of the House". I think investigating Obama is outside the scope of the office. 

Your second part lacked details ("nor have they played a role into the investigation of Democrats or Republicans who have been or now are arrested for criminal acts") but I looked up on Wikipedia House members arrested during Obama's term. Jesse Jackson Jr was listed, and since I was familiar with that case, I looked him up on the OCE website. The OCE did review the allegation: http://oce.house.gov/disclosures/Review_No_09-9812_Referral_to_Committee.pdf

Whatever source you are using seems confused about the scope and role of the OCE. It isn't the FBI for sure, but it reviews allegations and forwards them to the House Ethics committee for action.