LOS ANGELES (AP) — A Russian man who flew on a plane from Denmark to Los Angeles in November without a passport or ticket told U.S. authorities he didn't remember how he got through security in Europe, according to a federal complaint filed by the FBI.

Sergey Vladimirovich Ochigava arrived at Los Angeles International Airport on Nov. 4 via Scandinavian Airlines flight 931 from Copenhagen. A U.S. Customs and Border Protection officer could not find Ochigava on the flight manifest or any other incoming international flights, according to the complaint filed Nov. 6 in Los Angeles federal court.

He was charged with being a stowaway on an aircraft and pleaded not guilty in a Dec. 5 arraignment. A trial was scheduled for Dec. 26. A federal public defender representing Ochigava, who remained in custody Tuesday, didn’t immediately return a phone message from The Associated Press seeking comment.

The flight crew told investigators that during the flight’s departure, Ochigava was in a seat that was supposed to be unoccupied. After departure, he kept wandering around the plane, switching seats and trying to talk to other passengers, who ignored him, according to the complaint.

He also ate “two meals during each meal service, and at one point attempted to eat the chocolate that belonged to members of the cabin crew,” the complaint says.

Ochigava didn't have a passport or visa to enter the United States, officials said. Customs and Border Protection officers searched his bag and found what “appeared to be Russian identification cards and an Israeli identification card,” federal officials said in court documents. They also found in his phone a photograph that partially showed a passport containing his name, date of birth, and a passport number but not his photograph, they said.

Ochigava “gave false and misleading information about his travel to the United States, including initially telling CBP that he left his U.S. passport on the airplane,” the complaint says.

Scandinavian Airlines did not immediately respond to an email seeking comment.

Ochigava told FBI agents that he has a doctorate in economics and marketing and that he had last worked as an economist in Russia.

“Ochigava claimed he had not been sleeping for three days and did not understand what was going on,” the complaint said.

He told officials he might have had a plane ticket to come to the United States, but he was not sure. He also said he didn't remember how he got through security in Copenhagen and wouldn't explain what he was doing in the Scandinavian city, according to the complaint.