Mehran Karimi Nasseri, an Iranian refugee who lived for 18 years in Charles de Gaulle Airport in Paris and whose intriguing tale inspired the Steven Spielberg 2004 film “The Terminal,” died on Saturday in the same airport where he spent so much of his life.

Mr. Nasseri, who was in his late 70s, died of a heart attack in Terminal 2F at about noon, a representative for the airport said in a statement. His exact age was not immediately known.

Mr. Nasseri’s attachment to the airport persisted until his final days. He had been staying at a nursing home this year, but returned to the airport in mid-September “to live as a homeless person in the public space of the airport,” the representative said.

With his trimmed mustache and soft voice, Mr. Nasseri became a peculiar fixture in Terminal 1 of the bustling airport as he hauled piles of his belongings, stacked neatly on a luggage cart. He resided in the airport from 1988 to 2006, initially because of legal hurdles to prove his refugee status, and later by choice.

He lived between a pizzeria and an electronics store, planting himself on a red plastic bench that he made his home. On a coffee table, he had a hand mirror; an electric shaver, which he used every morning; and a collection of press clippings that told of his status as an odd figure in France.

His days were punctuated by the rhythm of flights, and by the presence of travelers, whose numbers swelled in the morning and dwindled at night, leaving him mostly alone to sleep on his preferred curved bench. Airport employees would routinely give him their meal coupons, and flight attendants would give him toiletries left over by first-class passengers.

The New York Times Magazine noted in a 2003 profile of Mr. Nasseri that he seemed “both settled — and ready to go.”

“I realize I am famous,” Mr. Nasseri said in that article. “I wasn’t interesting until I came here.”

His story became a bizarre tale in immigration history, and some details about his background proved difficult to pin down because of his changing claims about his origins. (In the same article, he denied that he was Iranian and deflected questions about his childhood in Tehran.)

Airport officials said they had confirmed that Mr. Nasseri was born in Iran, in the town of Masjid-i-Sulaiman, in 1945.

Early on, he had said he was expelled from his homeland for antigovernment activity in 1977 because, as a student in England, he protested against the government of Shah Mohammed Reza Pahlavi. When he returned to Iran, he found himself imprisoned and, soon, exiled.

He bounced around Europe for a few years with temporary refugee papers before arriving in Belgium, where he was given official refugee status in 1981. Mr. Nasseri traveled to Britain and France without difficulty until 1988, when he arrived at Charles de Gaulle Airport with a one-way ticket to London, a few clothes, about $500 and no passport.

He told airport authorities that his papers had been stolen at a Paris train station. Waiving the usual rules, the authorities let him fly to Heathrow Airport in London. But there, British immigration officials refused to let him enter the country, and he was returned to Charles de Gaulle.

Mr. Nasseri could not prove who he was or offer proof of his refugee status, so he moved into a holding area in the airport for travelers without papers.

He was there for days, and then weeks and months. As the months turned into years, and Mr. Nasseri became trapped in a legal twilight zone. In the 1990s, French authorities insisted that Mr. Nasseri was on French soil illegally, but they could not deport him because no country would accept him.

In 1999, he got permission to leave the airport and go wherever he wished in Europe. But he did not want to go anywhere, the airport’s medical director told The Times that year, because he was “scared to leave this bubble world” that he had been living in.

“Finally getting the papers has been a huge shock to him, as if he was just thrown from his horse,” Dr. Philippe Bargain, the airport’s medical director, said. “When you wait 11 years for something and suddenly in a few minutes you sign some papers and it’s done — imagine what a shock that is.”

He had made a home at Charles de Gaulle: Airport employees would call him Alfred or Sir, Alfred — a nickname rooted in a mistake that appeared in a letter from British immigration officials. He would wash up in the passenger bathrooms and take his clothes to the cleaner at the airport.

As his story spread throughout French news media and then to outlets across the world, reporters noticed the enthusiasm with which Mr. Nasseri would speak about the airport.

While the airport could not forcibly move or repatriate Mr. Nasseri because of a number of international refugee statutes at the time, his residence there appeared to depend on the kindness of strangers. People who heard his story sent him money in the mail. A traveler once gave him a sleeping bag and a camping mattress.

In the Spielberg film, Tom Hanks plays a refugee who is rendered stateless and becomes stuck in New York at Kennedy Airport after a military coup in his fictional homeland.

Charles de Gaulle Airport said in its statement on Sunday that its entire staff and community had cared for Mr. Nasseri “as much as possible for many years.”

But the airport noted that “we would have preferred that he find a real shelter, as he was suffering from psychological problems.”

Still, it appeared that Mr. Nasseri was content with his surroundings, living inside a place associated with freedom and frustration.

“The airport is not bad,” Mr. Nasseri told The Times in 1999. “It is very active and functions every day. I see different passengers every week from all over the world.”

Christine Chung contributed reporting.