Author Michael Crichton, photographed in New York in December 2004, challenged theories about global warming and the dangers of second-hand smoke. (Jim Cooper/Associated Press)

U.S. author Michael Crichton has died in Los Angeles, his literary agent has confirmed. He was 66.

He had been waging a private battle with cancer, according to a statement from his family.

Hugely influential in pop culture, Crichton was author of The Andromeda Strain, Disclosure, Jurassic Park and The Lost World, all made into movies.

Trained as a doctor, he was the creator and executive producer of ER and director of films such as Coma. He also co-wrote the screenplay for Twister.

Crichton's books portray scientific discoveries gone awry — germ warfare in The Andromeda Strain, gene therapy in Next and mind control in The Terminal Man.

He portrayed the failure of complex systems, such as the military-industrial complex, the medical testing system and corporate science and his engineers and scientists are unfailingly arrogant.

Many of the books deal with new scientific ideas, but his own attitudes toward scientific issues such as global warming have come under heavy public criticism.

He has disputed theories about things such as nuclear winter, the dangers of second-hand smoke and the causes of global warming and termed environmentalism "a religion."

But his stories, which torqued new scientific ideas into disaster scenarios, have been made into enormously successful movies, including Congo, Sphere, Timeline and The 13th Warrior.

His family issued a statement calling his work a challenge to scientists.

"While the world knew him as a great storyteller that challenged our preconceived notions about the world around us — and entertained us all while doing so — his wife Sherri, daughter Taylor, family and friends knew Michael Crichton as a devoted husband, loving father and generous friend who inspired each of us to strive to see the wonders of our world through new eyes," the family said.

"Through his books, Michael Crichton served as an inspiration to students of all ages, challenged scientists in many fields, and illuminated the mysteries of the world in a way we could all understand. He did this with a wry sense of humour that those who were privileged to know him personally will never forget."

Crichton directed the movies Westworld, The Great Train Robbery, Runaway and Coma and since 1994 has been creator of medical series ER. He won a primetime Emmy in 1996 for the series.

John Wells, executive producer of ER, remembered the tall, lanky Crichton as funny, erudite, gracious, exceptionally inquisitive and always thoughtful.

"No lunch with Michael lasted less than three hours and no subject was too prosaic or obscure to attract his interest," Wells said Friday.

"Sexual politics, medical and scientific ethics, anthropology, archeology, economics, astronomy, astrology, quantum physics, and molecular biology were all regular topics of conversation."

Crichton was born Oct. 23, 1942, in Chicago, but grew up in Roslyn, N.Y. His father was a journalist.

He initially studied English literature at Harvard, but quit to travel in Europe and then returned to go to medical school.

During the period he was in medical school, he wrote A Case of Need under the pseudonym Jeffery Hudson, which won the 1969 Edgar Award for best novel. The novel is about a pathologist trying to clear a friend of malpractice after a botched abortion.

He also wrote Odds On, The Venom Business and Zero Cool under the pseudonym John Lange.

In the early 1970s, he gave up medicine and moved to Hollywood, building his reputation with the 1973 film Westworld, about robot malfunction at an amusement park. He wrote and directed the film.

Crichton became a superstar with The Andromeda Strain, but his most successful franchise was Jurassic Park, which will soon have a fourth instalment. The Steven Spielberg-directed first movie is about dinosaurs, brought to life from old DNA, running riot in an amusement park.

Spielberg, a friend of Crichton's for 40 years, recalled him as an extraordinary talent.

"He was the greatest at blending science with big theatrical concepts, which is what gave credibility to dinosaurs again walking the Earth … Michael was a gentle soul who reserved his flamboyant side for his novels. There is no one in the wings that will ever take his place," Spielberg said.

A dinosaur, Crichtonsaurus bohlini, was named after him in honour of Jurassic Park.

Crichton is survived by his wife, Sherri, and daughter, Taylor.

With files from the Associated Press