The National Police Bureau (NPB) is the National Police Department for the Imperial Crownlands of Greater Hulstria and acts as the federal criminal investigative body. The NPB is a branch of the Ministry of Internal Affairs of Greater Hulstria but has its own governing body and is allowed by law to enact its own Bureau policy; the Imperial Diet, Hulstria's legislature, has its own oversight committee on the National Police Bureau, and to vote on the director.