It wasn't the first time Duterte has made shocking confessions in public. He has called himself more brutal than the Islamic State, and told a local radio station last month that he killed several criminals when he was the mayor of Davao.
But two days later, in an interview with CNN Philippines, the president said he was just kidding about his helicopter claim.
“We had no helicopter; we don't use that,” he told CNN, calling the literal interpretation of his early claim “creative imagination.”
The U.N. human rights chief, Zeid Raad al-Hussein, has urged Philippine courts to launch a murder investigation of a president who has “openly admitted to being a killer.”
Asked about this, Duterte told CNN: “I am playing you . . . your team knows I really want to say jokes.”
The president's spokesman had already told CNN that the helicopter killing actually happened. Duterte first made the claim during a speech on a northern island that had been hit by a deadly typhoon.
He announced that he was going to provide millions of dollars in aid to the victims, the Philippine Star reported, then changed the subject to the campaign against drugs and corruption that fueled his rise to power.
Vitaliano Aguirre II, Duterte's justice secretary, cautioned at the time that the president is prone to hyperbole and exaggeration, according to ABS-CBN News.
Whether Duterte's past lives up to his legend, the violence of his drug war is real. More than 6,000 people have been killed since he took office June 30. Some were gunned down during encounters with police who were acting under the government's orders, while others were killed by unknown vigilantes.
Duterte defended his anti-drug campaign in an October interview with Al Jazeera.
Killing criminals, he said, is not a crime.
“It could not be negligence, because you have to save your life. It could not be recklessness, because you have to defend yourself,” he said.
His goal, he said, is to eradicate his country's massive drug problems “to preserve the interest of the next generation.”
“If you destroy my country, I'll kill you. That's a legitimate thing,” Duterte said. “If you destroy our young children, I will kill you. That is a very correct statement.”
This post, originally published Dec. 28, has been updated. An earlier version said Typhoon Haiyan hit the Philippines in 2014. It was 2013.