Sponsoring "educational activities" for doctors is so financially lucrative that pharmaceutical companies are spending upwards of $200,000 on a single event, sparking fresh calls for a ban on industry funding.
The latest sponsorship disclosures from industry body Medicines Australia show drug company AstraZeneca spent the biggest amount on a single event - $241,000 - followed by Celgene and Novartis, between November 2016 and April 2017.
In terms of total spend on all events in the half-year period, AstraZeneca came second to Roche, which saw fit to splash $877,000 on 64 meetings, from breakfast symposiums to journal club meetings.
"Sponsorship is a key part of a company's marketing strategy, and we know industry money can lead to increased prescribing of drugs that tend to be newer, so there's less data on safety, and more expensive," said Alice Fabbri, an expert on corporate influence at the University of Sydney.
"They're profit-making multinationals, not charities, and if they're spending huge sums of money, it means they're getting a good return."
AstraZeneca spent $241,000 as the sole sponsor of the Lung Foundation's Australasian Lung Cancer Trials Group (ALTG) Lung Cancer Symposium in 2016, covering accommodation and meals at Hilton Hotel in Sydney, as well as airfares, transfers and other event costs.
The industry's code of conduct states the sponsor must not select the speakers, but Fairfax Media found the international guest speakers - Professor Keunchil Park from South Korea and Professor Glenwood Goss from Canada - have ties with AstraZeneca, accepting its research grants and holding advisory roles.
Both AstraZeneca and the Lung Foundation rejected suggestions the pharmaceutical giant had a say on the selection of speakers, with both saying an organising committee independently chose the speakers, attendees and educational content.
The two professors did not respond to a request for comment.
Dr Fabbri said that even if an independent committee made the final decisions, in such situations it was likely the sponsor could still be "subtly" exercising influence.
"The problem is that with industry funds, there is an implicit understanding that additional funds won't be offered in the future if the event doesn't present topics of interest to the company or the speakers aren't favourable," said Dr Fabbri.
"A recent analysis has shown that even a single sponsored meal worth $20 is associated with increased prescribing of the promoted medication."
The new data shows 33 drug companies shelled out $8.6 million on 1302 events attended by 231,000 healthcare professionals, including students and nurses, in the six-month period.
The Lung Cancer Symposium was the most expensive event, yet it only offered 12 hours of educational content over 1.5 days to 126 oncologists.
In contrast, the next three most expensive events - each topping $100,000 - offered on average 30 hours of educational content over four days to about 960 attendees.
The Lung Foundation said it was aware of concerns about undue risk of influence, but insisted industry funding was necessary because lung cancer was the leading cause of death from cancer, yet research funding for it was disproportionately low.
"This is the only national lung cancer research meeting of its type and is crucial to facilitating lung cancer research, developing stronger clinical research collaborations and designing new studies which will ultimately deliver better lung cancer care in Australia," said Professor Christine Jenkins, respiratory clinician and the foundation's chairwoman.
Associate Professor Nick Pavlakis, chair of ALTG, added: "The importance of attracting research funding and contributions from interested commercial and non-commercial entities ensures a sustainable lifeline to lung cancer research."
Dr Fabbri said one option was for the industry to place funds in a blind trust that could be controlled by an independent group.
"The end goal is a ban on industry funding, but there are some steps that can be taken in the meantime," she said.
A separate database shows 20 companies provided 145 sponsorships worth more than $200,000 each between October 2011 and September 2015.
Overseas, AstraZeneca forked out $US5.5 million in 2016 to settle charges following allegations it paid bribes and conveyed gifts, trips, and hard cash to healthcare officials in China and Russia.
In 2010, the company paid $US520 million in fines for illegally marketing to and manipulating American doctors with cash and luxury trips in order to increase sales of an anti-psychotic drug.
And in 2003, it paid $US355 million for defrauding the US Medicare system with a cancer drug marketing scam that involved bribing doctors.