Media giant Village Roadshow has donated a staggering $6.7m to Australia’s major political parties while successfully lobbying for tougher piracy laws, analysis shows.

Village Roadshow has been a prolific donor to the Liberals and Labor in the past two decades, and its contributions appear to peak during major debates about Australia’s copyright laws and online piracy.

By far the biggest yearly contribution ($1.2m) was made in 2015-16, at roughly the same time Australia’s parliament passed a major piece of legislation curbing online piracy.

On Wednesday, the Senate passed new powers allowing copyright owners to more easily block overseas piracy websites and force search engines to eliminate blocked pages from their results. The measures were supported by authors, screenwriters and musicians but criticised by Google, digital rights groups and copyright experts, who feared the legislation was so broad that it could threaten more innocent sites, such as meme-generators.

Village, one of the bill’s key backers, refused to tell Guardian Australia how much it donated to the parties in the months leading up to debate. Australia’s weak and sluggish donation disclosure requirements mean their contributions for 2017-18 will remain secret until at least February.

The Queensland University of Technology intellectual property and innovation law expert Matthew Rimmer said that made it impossible for the public to tell how Village may have attempted to influence the process.

“We should have real-time disclosure of donations,” Rimmer, a critic of the bill, said. “We don’t know at the moment whether Roadshow or other copyright owners contributed to the Coalition, ALP, Centre Alliance and the Greens. We don’t know whether ISPs and search engines made political donations to try to stop the bill.”

A Village Roadshow spokeswoman said the company complied with all donation disclosure laws.

“Village Roadshow does not comment on its political donations but would point out that the legislation referred to was passed with bipartisan support,” she said.

The fight against piracy – which has a significant impact on Australia’s creative industries – typically enjoys widespread support in parliament.

The Labor MP Ed Husic offered a rare criticism last month, saying the new measures were unlikely to have any practical impact on piracy. He said no one supported piracy, but accused “bloated, greedy, resistant-to-change rights holders” of failing to reform themselves to better cater to consumers.

Husic alluded to the impact of donations when saying parliament needed to keep the rights of consumers in mind.

“As lawmakers, just because we might get a selfie with Richard Roxburgh — I love Rake as much as anyone else — or a political party gets a donation from a rights holder, does not mean that we should stop looking at how to make the types of reforms that balance the needs of creatives and the needs of producers versus the needs of consumers,” Husic said.

The lobbying expert and University of Melbourne academic George Rennie said donations at the scale of Village Roadshow’s clearly bought access and influence.

“You might say that the policy is reasonable,” Rennie told Guardian Australia. “But it is that ultimate question of what is the reasonable policy that gets up. And the reasonable policy that gets up is almost always really monetarily well-backed.”

In its submission supporting the legislation, Village said despite the 2015 crackdown, search engines such as Google were still helping internet users find pirated content.

“The effects of piracy are shocking to our Australian employment, economy and way of life,” the company said. “The Australian film industry is critical to what we are as Australians.”

But the Australian Digital Alliance, which represents copyright users, said the bill was rushed, flawed and “worryingly broad and vague”. ADA executive director, Jessica Coates, said it potentially allowed for the blocking of innocent sites, including meme-generators.

“Its new ‘primary effect’ test significantly broadens its scope far beyond the piracy sites that were originally envisioned, and runs the risk of enabling the blocking of a large range of innocent and commonly used websites, such as meme-generators, auto-translation services and even VPNs,” Coates said in a statement on Wednesday.

“This is a significant departure from the stated intent of the scheme when it passed in 2015, which was to capture only ‘the worst of the worst’ websites.”