"We had no helicopter. We don't use that," he said. He described the incident as "just the creative imagination of this Tulfo."
Duterte did not clarify who Tulfo was, but he could have been referring to a number of journalists with the same surname.
Asked about calls by the United Nations to investigate claims by Duterte about killing others, the President seemed to poke fun at the media picking up on his every word.
"I am playing you, I am really like that, your team knows I really want to say jokes. When I say for example, when I pray ... like what God told me ... it is the same. And you spent time writing about it, criticizing, and that is your story, and you believe that."
In a televised speech Tuesday, Duterte said he had previously thrown someone off a helicopter and threatened the same fate to anyone misusing public funds.
"Whoever will use this (public funds) for corruption, I will get him (to) ride the helicopter with me going to Manila and will push him out while we we are up in the air," Duterte said. "Yes I will do that! I did that before and I can do that again."
When asked if the event actually happened -- and if the person killed was a kidnapper, as local media was reporting -- Martin Andanar, the presidential communications secretary, told CNN: "It happened; he said it."
Earlier this month, Duterte told a business forum that he personally had killed suspected criminals.
Sen. Leila de Lima, one of Duterte's top critics, said the comments were tantamount to admitting he participated in a mass murder and were grounds for impeachment.
The drug war
Though his admissions of killing, off-color comments
and abrasive approach to international politics
have drawn international interest and scrutiny in Duterte's nascent presidency, it's his drug war that affects the daily lives of Filipinos.
Tackling rising drug consumption and production was one of his key campaign planks during the country's elections earlier this year.
Duterte promised to vigorously combat the problem and has waged a bloody campaign against the drug trade since taking office.
Nearly 6,000 people have been killed in the drug war since July
, according to the Philippines National Police.
Despite the killing admissions and rising body count, Duterte remains extremely popular in the Philippines, with polls showing
a high percentage of the country remains supportive and trusting of the President.