n extensive federal review of autopsy data has found that the powerful painkiller OxyContin is suspected of playing a role in the overdose deaths of 282 people in the last 19 months, more than twice the number in some previous estimates. The nation's top drug enforcement official recently called the new finding "startling."

The review also found that virtually all the deaths were of people who swallowed the pill whole or crushed into powder, further suggesting that OxyContin misuse may be more difficult to curb. The overdose deaths were previously believed to have been of people who injected or snorted crushed pills, which are quicker and more dangerous forms of drug delivery.

Meanwhile, officials of Purdue Pharma, OxyContin's manufacturer, acknowledged in a recent interview that even after reports that OxyContin had been getting into the wrong hands, the company continued for a while this year to distribute free seven-day supplies of the drug, through doctors, to promote its use.

The federal study on OxyContin, by the Drug Enforcement Administration, is the agency's first to explore links between overdose deaths and a brand name drug. Previous reviews had looked only at drugs' active ingredients, used by many manufacturers. Besides the 282 deaths, which often also involved other drugs and alcohol, federal officials said they found that 500 people had died since the start of 2000 from overdoses involving oxycodone, the active narcotic in OxyContin and other popular painkillers. But federal officials could not say whether the oxycodone linked to those deaths was from OxyContin, a drug for the treatment of severe and chronic pain.

Asa Hutchinson, the administrator of the Drug Enforcement Administration, called the study's results startling and said, "This verifies the fear and concern that we have had about this drug."

Dr. Paul Goldenheim, the vice president for research and development at Purdue Pharma, said that the Drug Enforcement Agency's data was consistent with the company's own findings. But he emphasized that none of the information implicated OxyContin in any of the reported deaths. "There is no suggestion that the 200 subjects died from oxycodone," Dr. Goldenheim said. The study did not try to determine whether OxyContin alone was responsible for the deaths because the overdose deaths typically involved multiple drugs.

Federal officials have said that abuse of OxyContin has grown faster than abuse of any other prescription drug in decades. Purdue Pharma heavily promoted the drug as safer than other narcotics because its active ingredient was in a time-release mechanism. But abusers quickly learned that crushing the pill disarmed that feature.

Fewer than 10 of the 282 people whose deaths were associated with OxyContin were intravenous drug abusers, and only one showed signs of having snorted the drug.

That finding, federal officials said, suggests that a recent decision by Purdue Pharma to reformulate the time-released painkiller to reduce its abuse by injection or snorting may have limited benefits.

Dr. Goldenheim, the company executive, said that he also believed that more steps would be needed to curb the drug's misuse. " We have been concerned that the reformulation will not solve the bulk of the problem," he said.

Dr. David Gauvin, a pharmacologist at the Drug Enforcement Administration, said medical examiners in 30 states had so far reported about 1,010 overdose deaths involving oxycodone since January 2000.

Based on responses to date, the agency concluded that OxyContin was "directly linked" as a factor in 110 overdose deaths because tablets were either found in a person's stomach or a prescription for the drug was found on a body. Other confirmation came from reports on interviews with witnesses.

"You may have had a credible witness who said, `My son took OxyContin, and 20 minutes later he stopped breathing,' " Dr. Gauvin said.

Agency officials classified 172 deaths as "OxyContin possible," cases where autopsy reports showed high blood concentrations of oxycodone without the presence of other compounds like aspirin or acetaminophen. While OxyContin contains only oxycodone, other narcotics, like Percodan and Tylox, use the drug as an active ingredient but also include other compounds.

In 501 cases, the agency did not receive enough information to differentiate between OxyContin and oxycodone, its principal ingredient. And the information in 227 of the 1,010 reports was insufficient to enable the agency to analyze them.

Purdue Pharma executives have defended their decision to distribute free OxyContin pills.

The company's salespeople gave doctors promotional material about OxyContin that contained cards, which doctors would then give to patients along with a OxyContin prescription. A patient would bring the card to a pharmacy for free drugs.

Michael Friedman, the chief operating officer of Purdue Pharma, based in Stamford, Conn., said the sampling program was used to acquaint patients with OxyContin. Mr. Friedman said the company had begun a new card program in July but stopped it a few days later when the Food and Drug Administration placed the highest possible warning on OxyContin's label.

Asked why Purdue continued to offer free supplies in the face of mounting reports of abuse, Mr. Friedman said he believed that people who received the cards from doctors were legitimate patients. He estimated that the company had run four or five similar marketing programs for the drug in recent years and that from 8,000 to 15,000 cards had been distributed each time.

"The fact that we're providing a sample to a patient has no connection to some criminal doctor who was taking money for prescriptions," Mr. Friedman said.

Terry Woodworth, the deputy director of drug agency's division of diversion control, said Purdue Pharma's program did not violate the law. But Mr. Woodworth, who learned about Purdue Pharma's program from a reporter, said he was stunned to hear that the company continued it after reports about abuse. "It's absolutely absurd," Mr. Woodworth said. "Were they meeting the letter of the law? Sure. Were they meeting the intent and spirit? No."