These companies have controversial pasts. Google AI didn't tell us

Google's AI overview draws on a range of sources it deems reliable, which often includes a company's own website. (ABC News: Danielle Bonica)

Philip Morris International is a company with a controversial history.

The tobacco giant has been accused of aggressively marketing addictive, cancer-causing cigarettes and fuelling smoking-related deaths and diseases around the world.

But when a colleague doing some research recently put the company into Google for a search, the result they received surprised them.

Their search produced a summary from Google's AI overview, a feature that generates "a snapshot of key information about a topic or question" at the top of some Google search results.

The AI overview summaries often include links back to source material, and this one drew heavily from sources published by the company itself.

And the Philip Morris AI overview produced by Google on this occasion was pretty upbeat.

Philip Morris International (PMI) was "a leading international tobacco company working to transition from cigarettes to smoke-free products," the AI summary said, citing Philip Morris International's website.

"The company is focused on a 'future without cigarettes' and is actively involved in reducing post-consumer waste (filter cleanup), and improving sustainability within its supply chain," it read.

This Google AI overview was produced in April, but the overview presented to separate users can differ based on a range of factors. (Google)

University of Sydney public health professor Becky Freeman said she was shocked to read an AI overview that was, in her view, "essentially a regurgitation of Philip Morris International's PR materials", with no mention of negative press around the company.

Professor Freeman is not a neutral observer. Her research examines how the tobacco industry continues to promote its products, despite known harms and advertising restrictions.

She said Google's AI overview for Philip Morris parroted marketing strategies employed across the tobacco industries, where companies try to "make it seem like their bad behaviours are in the past", while continuing to profit from the sale of cigarettes.

"I consider this to be incredibly misleading," she said, after examining example AI summaries provided by the ABC and conducting her own search.

The ABC's initial AI overview results did not mention any broader context around the company's history or links to tobacco-related harms.

"It gives the impression this is just an everyday, run-of-the-mill company that is doing its best to run sustainably, and that engages in re