"Our report on the fact that J&J was aware of small amounts of asbestos in its talc, in its baby power, in the ore that it mined in Vermont to make baby power, is based entirely on their documents," Girion told CNBC's "Power Lunch" on Friday.
The Reuters story sent J&J shares down 9 percent on Friday and prompted a response from the health-care company that called the article "one-sided, false and inflammatory."
"Simply put, the Reuters story is an absurd conspiracy theory, in that it apparently has spanned over 40 years, orchestrated among generations of global regulators, the world's foremost scientists and universities, leading independent labs, and J&J employees themselves," the company said in a statement.
In addition to the internal J&J documents from 1971 to the early 2000s, Reuters also reviewed depositions and trial testimony.
"We see that historically in the '70s, '80s, that era, there were company memos and reports where they're talking about asbestos, fretting about it, what to do about it, how to detect it, how to get rid of it," Girion said.
"During that era they certainly were talking about it. Today, their position is that nothing in those reports is actually asbestos that got into baby powder," she added.
There is also "no evidence" that they are currently selling any products with asbestos in it, Girion pointed out. On Friday, J&J said its baby powder is "safe and asbestos-free."
Johnson & Johnson has been hit with a wave of lawsuits alleging the company's talc baby powder contained asbestos and caused cancers. The results have been split, with some juries siding with J&J and others unable to reach verdicts. In July, a Missouri jury ordered J&J to pay $4.69 billion in a case involving 22 women and their families. J&J has vowed to appeal the verdict.
— CNBC's Angelica LaVito contributed to this report.