A tobacco industry lawyer sought to fend off accusations that cigarette makers waged a deceptive campaign to blunt concerns over secondhand smoke as he testified on Wednesday in the government’s $280 billion suit against the industry.

Industry lawyer John Rupp repeatedly denied allegations that he had helped orchestrate an effort to use industry-paid scientists to downplay the issue during the 1980s.

Rupp said the industry sought out scientists and paid them to make an “objective appraisal” of whether secondhand smoke was harmful to non-smokers, a move they hoped would dispel the “extreme views” of some anti-smoking activists.

“It was important to find out what the truth was,” Rupp, a partner with Covington and Burling, told the presiding judge, U.S. District Judge Gladys Kessler.

But Justice Department lawyer Sharon Eubanks showed the judge industry memos in which other industry officials said the initiative was designed to refute academic and government studies linking secondhand smoke to diseases such as lung cancer.

Rupp worked on the issue of secondhand smoke as a lawyer for the industry-funded Tobacco Institute and individual tobacco companies from 1981 to 1995.

The government suit, launched in 1999, targets Altria Group Inc. and its Philip Morris USA unit; Loews Corp.‘s Lorillard Tobacco unit, which has a tracking stock, Carolina Group; Vector Group Ltd.‘s Liggett Group; Reynolds American Inc.‘s RJ Reynolds Tobacco unit and British American Tobacco Plc unit British American Tobacco Investments Ltd.

The Justice Department charges that cigarette makers conspired for 50 years to lie and confuse the public about the dangers of smoking. The trial is in its sixth week.

The companies deny the allegations and say they have drastically changed their marketing practices since 1998, when they signed a landmark pact with state attorneys general that severely restricts marketing and keeps them under oversight.

Rupp said the scientists, who came from prestigious institutions such as Georgetown University and the University of Massachusetts, did not consider themselves to be working “on behalf” of cigarette makers even though they were being paid by the industry.

“We were paying them to share their views in forums where they would be usefully presented,” Rupp said.

The U.S. Surgeon General concluded in 1986 that secondhand smoke increases the risk of lung cancer in non-smokers, and several years later the Environmental Protection Agency listed it as a human carcinogen.

Eubanks showed the judge memos from other tobacco industry officials over the years that described the research initiative as a “weapon” to be used in a “battle” with anti-smoking groups, and that part of Rupp’s job was to “horse-shed” scientists to make sure they stuck to the tobacco industry line.