The top executive of a leading tobacco company defended his past statements on Capitol Hill about cigarettes' addictiveness and health effects yesterday, as the increasingly beleaguered industry found itself under attack in the House and from members of the Senate. In addition, the Justice Department said that it was looking into possible criminal charges based on congressional testimony by seven industry executives in April.

Thomas E. Sandefur Jr., CEO of the Brown & Williamson Tobacco Co., yesterday told the House Energy and Commerce subcommittee on health and the environment that he stands by his previous testimony and called congressional and executive branch inquiries into his industry's practices "McCarthyism."

On Tuesday, Food and Drug Administration Commissioner David A. Kessler appeared before the subcommittee and presented evidence that Brown & Williamson secretly developed a high-nicotine strain of tobacco overseas and boosts the nicotine released by its cigarettes by doping the tobacco with ammonia compounds.

Those findings, he said, "lay to rest any notion that there is no manipulation and control of nicotine." Kessler has said that if the agency determines that manufacturers intend that their products be sold as drugs -- with manipulation a key element of proof -- then tobacco products could fall within the FDA's regulatory ambit, potentially leading to restrictions on nicotine levels. The subcommittee is considering regulation that would guide the FDA on tobacco issues.

Sandefur denied that his company manipulates nicotine levels and said that Kessler's testimony was "no more than grandstanding." Sandefur accused Kessler of trying to "set Brown & Williamson up" to appear to be lying, and insisted that there was nothing "sinister and secretive" about the high-nicotine plant line.

He said the so-called Y-1 tobacco, which has made its way into several of the company's cigarette brands, was consistent with past requests by U.S. public health officials, notably former National Cancer Institute scientist Gio Gori (later a consultant to Brown & Williamson) for "cigarettes which would deliver lower levels of tar and moderate levels of nicotine." The cigarettes using the Y-1 leaf, Sandefur said, "delivered essentially the same nicotine as the products they replaced."

FDA spokesman Jim O'Hara said, "Once you get past the personal attacks, the company confirmed today the facts we presented to the subcommittee on Tuesday" by explaining in detail the ways that the company can fine-tune nicotine levels.

Sandefur said that his company views nicotine not as a drug but as a flavoring for cigarettes, and does not design its products with the pharmacological effects of nicotine in mind.

Rep. Ron Wyden (D-Ore.) questioned Sandefur about "Project Wheat," a 1975 study conducted for a B&W sister company, British-American Tobacco Co., on smoker attitudes. (The companies, under parent British-American Tobacco Industries, pool research money and share research results.) The Wheat study, provided to the subcommittee by B&W, focused on the smoker's "inner need level," which the study said was "related to his preferred nicotine delivery."

Part of that study suggested that there was a market niche waiting for cigarettes that provided low tar and high nicotine. ("Tar" is a catchall term for the gummy substance generated when tobacco burns. Tar and nicotine levels generally go hand in hand unless the tobacco or cigarette is modified.) About the time of the Wheat study, the company brought out Barclay, a low-tar brand that a 1983 New England Journal of Medicine article identified as delivering an exceptionally high charge of nicotine.

Wyden said that in light of Project Wheat, "It sure looks to me that you all are in the drug-making business." Sandefur replied that he had not heard about Project Wheat before the hearing, and "we don't design our products that way."

Lawmakers also presented documents that they said showed that B&W simultaneously had mounted an aggressive media campaign, "Project Truth," to play down the smoking-cancer link and cosponsored research showing that mice painted with tobacco compounds developed tumors.

Sandefur generally refused to answer questions about scientific studies or documents that were prepared before he came to the company more than a decade ago, saying that he could not become an expert on all 7,000 pages of documents his company had provided to the committee. After one such demurral, subcommittee Chairman Henry A. Waxman (D-Calif.) said, "Wouldn't you expect that you should, as CEO, be knowledgeable about something that is clearly the issue of the day?"

Although Sandefur was alone in the spotlight yesterday, other tobacco company executives could come under new pressure from the Department of Justice. Department lawyers revealed yesterday that they have begun studying whether to pursue a criminal investigation of tobacco company executives after a series of allegations lodged by members of Congress that cigarette officials had engaged in a number of illegal acts to protect their industry.

Rep. Martin T. Meehan (D-Mass.) and six other House members charged in a recent letter to Attorney General Janet Reno that tobacco companies may have committed mail fraud and wire fraud, as well as conspiracies to obstruct Congress, restrain trade and defraud the public, by withholding scientific information "concerning the health hazards of tobacco use and the addictive characteristics of nicotine."

Yesterday, Reno said that "we are looking at all the allegations, all the comments, all the information that we have received to determine what would be the appropriate action by the Justice Department in terms of a variety of issues." That effort could involve, in addition to the criminal division, the department's civil and antitrust divisions "and all the divisions that might have some impact, to see what the appropriate action would be, if any."

A Justice Department source described the department's consideration of criminal violations as at the "inquiry" stage, when lawyers must make an assessment of whether federal laws were violated. No full-scale investigation involving the deployment of law enforcement officials has been initiated, the source said.

During a break in yesterday's hearing, one of Sandefur's lawyers, former attorney general Griffin B. Bell, said that his client and the other executives had only been expressing their opinions in their congressional testimony last April, and "we don't put folks in jail for things like that in this country -- so far."

There were also indications yesterday that the tobacco industry may sustain further attacks at the state level.

Last month, Mississippi Attorney General Michael Moore filed a lawsuit seeking compensation from tobacco companies for Medicaid expenses due to smoking-related illnesses; shortly thereafter, Florida paved the way for a similar suit. In a telephone interview yesterday, Moore said that he had been in preliminary discussions with the Justice Department to encourage federal officials to file a similar lawsuit seeking reimbursement of Medicare funds.

Yesterday, Sens. Tom Harkin (D-Iowa) and Frank R. Lautenberg (D-N.J.) announced that they would soon introduce legislation to allow the federal government to file a similar suit.

Toward the end of yesterday's hearing, Wyden urged Sandefur and other tobacco executives to work with lawmakers to develop regulations they can live with, or be more and more "marginalized" and "outcast" in the debate over America's tobacco policy.

"Congressman, it's hard for me to envision becoming more of an outcast than I am," Sandefur responded.

Staff writer Pierre Thomas contributed to this report.