per my agency who facilitate my employment with qp, police clearance is a new requirement by qatar gov before processing any visa. it should be authenticated "red ribbon" by your appropriate gov department and also authenticated by qatar embassy in your country. it took me three weeks before i accomplished that police clearance. the hardest part was in qatar embassy for they entertain about 60 applicants per day on a first come first serve basis. I even experienced queing by midnight in order to be accomodated on the list.
..and now still waiting for my work permit.