US officials have charged a man with being a stowaway after he disembarked in Los Angeles from a Copenhagen flight without a ticket or passport.
Sergey Ochigava, 46, had Israeli and Russian ID cards with him, newly released charging documents show, but his citizenship is currently unknown.
Officials say he did not attempt to hide on the plane and tried to chat up other passengers over the 12-hour trip.
He has pleaded not guilty and is due in court later this month.
After arriving in LA on 4 November, Mr Ochigava initially told US customs officials that he had left his passport on the plane, but no passport was ever found.
Officials could find no record of him being booked for any flights to the US or having requested any visa for entry.
In interviews with US investigators, Mr Ochigava said that he "might have had a plane ticket... but was not sure", according to the federal indictment.
He added that he had no memory of how he found himself on a Scandinavian Airlines flight to the US, explaining that he had not slept for three days, and did not know how he got through security at the airport in Denmark.
Officials were also unable to determine how he came to be in Denmark in the first place before departing for the US.
He said he last worked as an economist in Russia "a long time ago".
Airline crew members said he moved throughout the plane, switching seats several times. They did not notice that they had flown with an extra passenger until they were contacted by investigators.
Mr Ochigava "asked for two meals during each meal service, and at one point attempted to eat the chocolate that belonged to members of the cabin crew", the indictment said.
One flight attendant told investigators that it looks like he "was trying to talk to other passengers on the flight, but most of the passengers ignored him".