Yevno Azef - terrorist double agent
historyYevno Azef was Russia's leading terrorist and most highly paid police informant. In 1904 he organized the assassination of Vyacheslav Plehve who was minister of the interior and a person who initially recruited him. This gave him a lot of credit in Socialist Revolutionary Party, which in turn allowed him to give away a lot of party members to the secret police without being suspected of treason.