sue sim , who came to national prominence five years ago as northumbria police dealt with the raoul moat manhunt , said she was ` sad ' to leave the force but was retiring to spend more time with her family .
it was announced last month that ms sim was to be investigated by her police and crime commissioner 's office for alleged .
although she was not suspended after the accusations were made against her .
she described the search for moat following the murder of christopher brown and shooting of one of her own officers , pc david rathband .