The New York Times reported on its front page yesterday that an article on Cambodia published in its Sunday magazine last December was a hoax.

The author of the article, "In the Land of the Khmer Rouge," never left Spain, The Times said. He simply invented his dispatch, a dramatic account of a dangerous visit to Khmer Rouge territory in the Cambodian mountains, lifting parts of it from other published works.

Responding to an article in The Washington Post that raised questions about the authenticity of the report, the editor of The Times Magazine, Edward Klein, and two Times correspondents traveled to Spain's Mediterranean coast to interrogate the 24-year-old author of the article, Christopher Jones. After insisting for two days that his article was genuine, Jones finally acknowledged Sunday that he had invented the entire tale, The Times reported yesterday.

"It was a gamble--that was it," The Times quoted Jones as saying Sunday in Calpe, Spain, where he lives. "Unfortunately, the gamble was too big, and wasn't sufficiently researched or tied down," Jones continued, according to the newspaper. "The gamble was a mistake," he concluded.

James M. Markham, The Times' correspondent in Madrid, tracked Jones down Friday, the day after a story appeared in The Post raising the possibility that his article was a fabrication. Markham found Jones in a hilltop villa in the seaside town of Calpe.

Jones shares the villa with Eva Fitzek, a 52-year-old German physiotherapist, who initially sought to hide the writer from Markham, he reported in yesterday's Times. Saturday Markham was joined by Klein and Sunday by Henry Kamm, until recently The Times' Asian diplomatic correspondent based in Bangkok.

These three conducted the interrogation that led to Jones' confession Sunday.

A. M. Rosenthal, executive editor of The Times, issued a statement taking responsibility for publishing Jones' hoax. The Times has procedures for checking the accuracy of articles it publishes, Rosenthal said, "but in this case, these procedures failed to uncover the clues in the text that would have led us to doubt the veracity of the piece.

"The major mistake we made," Rosenthal continued, "is in not following our customary procedures in showing an article in a specialized subject by any writer without outstanding credentials in the field to one of our own specialists.

"I regret this whole sad episode and the lapse in our procedures that made it possible," Rosenthal said.

In his piece Jones borrowed material from an article he himself wrote for Time magazine's Asian edition after a brief 1980 trip into Cambodia, and from a variety of other published sources. He lifted one passage from a book by Prince Norodom Sihanouk, Cambodia's leader until 1970, and another from a 1930 novel about Cambodia, "The Royal Way," by Andre Malraux.

On Sunday Jones explained his use of the Malraux material by saying, "I needed a piece of color."

Jones submitted some of the material later published in The Times to Time magazine last fall, but Time rejected it, doubting its authenticity. Sources at The New York Times said the original Jones manuscript was written in vivid, almost purple prose, and read like "something that wouldn't have gotten into a high school newspaper," according to one journalist who read it.

Klein, editor of The Times Magazine, published a heavily edited version of the original 11,000-word story after checking Jones' reference with Time magazine, which had published Jones' earlier dispatch in 1980. But Klein apparently did not look up the actual piece Jones wrote for Time's Asian edition, portions of which appeared verbatim in the article that The Times published in December.

Nor did Klein show the manuscript to other journalists on The Times with expertise in Cambodian matters, informed sources at the paper said yesterday. This was a lapse in procedures that Rosenthal noted in his statement yesterday.

In January columnist Alexander Cockburn reported in The Village Voice that Jones had lifted a passage from the Malraux novel. This prompted The Times Magazine to write a letter to Jones asking for an explanation, and canceling an assignment the magazine had given him to report from Kurdistan. Klein said efforts were also made to contact Jones by telephone, but no other action was taken until The Post story appeared last Thursday.

That story reported that Khmer Rouge officials in Bangkok said Jones had not visited Khmer Rouge territory nor interviewed the officials he quoted in his story, purportedly based on a visit last fall. The Post story also pointed out the similarities between Jones' 1980 Time magazine account and his article in The Times Magazine.

According to Markham's account in yesterday's Times, it wasn't easy to shake Jones from his story. When he finally gave up the ghost, this was his reaction, according to Markham:

"Shaken by the unraveling of his story, Jones fell mute. Then, urged on by his questioners, he confessed the hoax. 'I wanted to do the job, but I couldn't,' he said. 'I had to do my best from what I had, and consequently reconstructed it.' "

Jones would not pass moral judgment on his own behavior, Markham reported. Asked if he felt worse about his hoax or the fact that he was caught, Jones replied: "Maybe it's too early to tell. Maybe it's fair to say that I'm still in a state of shock."

The Times was the third major newspaper to be deceived by a hoax in the last 10 months. Last April Janet Cooke, a reporter for The Washington Post, acknowledged that she had invented a story about an 8-year-old heroin addict that had just won a Pulitzer Prize. The Post gave back the prize and Cooke resigned from the paper. The same month a columnist for The New York Daily News, Michael Daly, resigned from that paper after British authorities accused him of fabricating a column written from Northern Ireland.

In an interview yesterday, Rosenthal drew an implicit distinction between the Jones case and those two earlier episodes. The Times' system for checking the authenticity of the material it publishes "is not hoax-proof against outside writers," Rosenthal said. "I guess we're all naive" about the possibility of outright fraud by a writer, Rosenthal added.

Rosenthal said there would be no personnel changes at The Times as a result of this incident. "I'm not looking for any goats in this, frankly," he said.

Today's editions of The Times carried an editorial on the hoax. Headlined "A Lie in The Times," it said, in part:

"We leave exploring the psychology of such adventurers to others. The Times' responsibility is keenly felt. As we have previously observed, the lie--the fabricated event, the made-up quote, the fictitious source--is the nightmare of the newsroom. It is intolerable not only because it discredits publications but because it debases communication. It may not be too much to say that, ultimately, it debases democracy."