LISBON, Portugal (AP) — Portuguese Prime Minister António Costa said Tuesday he is resigning after being involved in a widespread corruption probe. Costa said in a nationally televised address that “in these circumstances, obviously, I have presented my resignation to the president of the republic.” Costa's shocking announcement came hours after Portuguese police arrested his chief of staff while raiding several public buildings and other properties as part of a widespread corruption probe. The Supreme Court, the state prosecutor’s office said, was also examining the suspects’ “use of the prime minister’s name and his involvement to unlock” the practices being probed.