Aoun, who has been accused of being a puppet of the Iran-backed Hezbollah militia group, made the statements to Italian media Corriere della Sera on Tuesday, parroting a previous denial by the designated terrorist group.
He said that Hezbollah did not store weapons in the port but the lead will be pursued further.
“Impossible, but serious events like these light up spirits and imagination,” Aoun said when asked about people advancing the theory. He added, however, that “even this lead will be investigated”
Authorities are probing the devastating blast on Aug. 4 that killed over 200 people and injured 7,000 more, which resulted when 2,750 metric tons of ammonium nitrate stored in Beirut's port without the necessary safety precautions were engulfed in flames.
Aoun said the investigation is considering whether neglect, an accident or “external interference” caused the blast.
Hezbollah leader Sayyed Hassan Nasrallah has alluded to the theory that Israel — a major foe – is to blame for the explosion, but Israel has denied any involvement.
“Although it seems that (it) has been an accident, I want to avoid being accused of not having listened to every voice,” Aoun told the Italian daily.
The president said that claims of airplanes flying by the port just before the blast are “not very credible” but will be investigated further.