Philip Hilts, a science reporter for The New York Times who exposed a tobacco company's decades-long cover-up of its own research showing that tobacco was harmful and nicotine was addictive, died on April 23.

His son Ben said that the cause was related to the disease.

Mr. Hilts wrote for The Times, The Washington Post and other publications and was the author of six books on scientific, medical and social topics.

His work on tobacco made headlines across the country. In 1994, he obtained internal documents showing that executives of the Brown & Williamson Tobacco Corporation were struggling with whether to tell the surgeon general about the dangers of smoking because of their own research showing that cigarettes were addictive and caused lung cancer.

Mr. Hilts wrote that the executives of Brown & Williamson wanted to keep their research results secret, to stop work on a safer cigarette, and to pursue a legal and public relations strategy of admitting nothing.

Mr. Hilts's article appeared on the front page of The Times a month after top executives of the seven biggest American tobacco companies testified before Congress that nicotine was not addictive. Two years later, they were all under federal investigation for possibly lying under oath and were no longer leading their companies.

The executives had been under criminal investigation by the Justice Department. In 1998, four tobacco companies and 46 states reached the largest civil litigation settlement in American history, with the companies agreeing to pay the states $206 billion over 25 years. The internal company documents that Mr. Hilts and other news organizations relied on were made public.

Major stories about breast implants, contraceptives and deception in the cosmetic device industry were broken by Mr. Hilts. He was one of the first reporters to cover the AIDS epidemic.

He was a scuba diver and world traveler, and he wrote a dispatch from an active volcano a mile below the Pacific Ocean. He covered the confessions of a person who claimed to have AIDS. He looked at the use of hypnotism in law enforcement, and found that it led to the release of four men from prison.

He was the director of the Knight Science Journalism Program at the Massachusetts Institute of Technology.

Smokescreen: The Truth Behind the Tobacco Industry Cover-Up is one of his books.

ImageMr. Hilts was the author of six hard-hitting nonfiction books on scientific, medical and social topics.
Mr. Hilts was the author of six hard-hitting nonfiction books on scientific, medical and social topics.
Mr. Hilts was the author of six hard-hitting nonfiction books on scientific, medical and social topics.

Philip James Hilts was born in Chicago. Edward was a nonfiction writer who wrote historical fiction for children. His mother worked at a Sears store as a switchboard operator.

Philip grew up in a suburb west of Chicago.

He attended Georgetown University in Washington from 1966 to 1967. When the hippie and counterculture movements were in full bloom, he dropped out and went to San Francisco to participate.

He decided to become a journalist after returning to Georgetown in 1969 but never graduating. He worked as a reporter and photographer at small suburban newspapers in Washington, D.C., and Denver before becoming a magazine writer.

He was a staff writer for The Washington Post in the 1980s and took time out for a fellowship at Harvard. He worked for The Times in Washington as a staff writer until 1996, when he became a contract writer.

Mr. Hilts received a journalism fellowship that sent him to teach journalism in Africa. Most of his fellowship was devoted to science writing.

Mary Donna McKeown, a fellow reporter at The Washington Daily News, died in 1987. He married Carisa Cunningham in 1993 and they divorced in 2011. He married a researcher in math and science education. They lived in Cambridge, Mass., and Rochester, Vt. He died in the hospital.

He is survived by his wife, two daughters, a grandson, four brothers, two sisters and two children.

Mr. Hilts was finishing a book about Lynn Margulis, a scientist who discovered the origin of cells and was married to the astronomer Carl Sagan.