The analysis has been published to coincide with the Australian Electoral Commission's release of annual disclosures for the past financial year.
Independent Senator Jacquie Lambie condemned the findings of the analysis - saying it showed "what is wrong with politics these days”.
“If people in Australia don't find that sickening I suggest that you do - because I can tell you now it is as corrupt as hell,” she told SBS News.
“You could not water down these political donations any further - they are absolutely disgusting - they make me sick.”
Centre for Public Integrity director Joo Cheong Tham said an overhaul of the system was needed to increase transparency.
“The federal disclosure scheme is mis-named – it is a non-disclosure scheme with more than a third of political funding shrouded in secrecy,” he said.
Big money continues to dominate donations
The release of the latest disclosures on Monday showed big money continues to dominate - with almost half of all federal political donations over the past year coming from just four companies and one industry group.
This included the largest single donor - billionaire mining magnate Clive Palmer's Mineralogy, which gave $5.9 million to his own United Australia Party.
Other big donors included Pratt Holdings ($1.55 million), Woodside Energy ($335,415), Macquarie Group ($251,230) and the Australian Hotels Association ($232,301).
Pratt Holdings owner Anthony Pratt memorably held a rally at one of his factories in the United States with Prime Minister Scott Morrison and President Donald Trump back in 2019.
The Minerals Council of Australia donated a total of $145,700 - including $27,500 for membership of the Liberal Australian Business Network, $22,000 for the Nationals policy forum and two payments totalling $55,000 for the federal Labor business forum.
“We need donation laws that stop the influence of big money on decision making that stop democracy being for sale,” Greens Senator Larissa Waters said.
“People deserve to have there democracy back they should know that people are making decisions for them with the public interest at heart.”
The Greens plan to introduce a new bill to ban those bidding for government work from donating to political parties.
The Centre for Public Integrity has also suggested reducing the disclosure threshold to $1,000 and introducing real-time reporting to enhance transparency.
The group also wants to set a donation cap at $2,000 per annum per candidate and $5,000 per political party.
The Liberal, National and Labor parties have in the past opposed major reforms to the disclosure system, such as a cap on the amounts paid by individuals, companies and unions.
The three major parties did support a ban on foreign donations in 2018.
Independent Senator Rex Patrick told SBS News the Labor and Liberal party were operating as a donations “cartel” preventing reform from taking place.
“It's a breeding ground for corruption and improper influencing of politicians and particularly when things are done behind closed doors it creates problems,” he said.
“We need to stop that - we need to make sure we have a fully transparent process.”
Labor leader Anthony Albanese said his party discloses all donations above $1,000, even though they are not required to by law.
“That’s what Labor does because we believe in transparency and we think that should be the law,” he told reporters.
“This Coalition government of course don’t believe in transparency - they don’t believe in accountability.”
Assistant Treasury Minister Michael Sukkar said political parties should follow disclosure rules.
“The current rules that are in place ensure that political parties are required to disclose large donations,” he told reporters.
“The real question is ensuring that political parties meet those requirements.”