A security source at Cairo airport said the authorities concluded that the man, Hamad Fahd Jassem, 30, had mental and nervous problems and did not mean any harm.
"He did not intend to harm the passengers or the plane or divert the plane by force, so there is no need for us to detain him," said the source.
Airline spokeswoman Salam al-Shawa said earlier that the man had tried to hijack the plane to Geneva but security sources in Cairo said he carried nothing with which to threaten the crew.
Egyptian authorities removed the passenger and his Kuwaiti travelling companion from the plane, which was travelling from Casablanca in Morocco to the Qatari capital Doha with a stop in the Libyan capital Tripoli.
Jassem had alarmed the crew and passengers by talking incoherently, harassing passengers and trying to grab the public address system, the security sources at Cairo airport said.
After questioning Jassem in Cairo, doctor Nehad Gamaleddin quoted the man as saying that after taking off from Tripoli he felt he was choking and had to stand up to relax.
Jassem has said he intends to fly on to Kuwait on another plane later on Saturday, the sources said.