Yet visitors to the parkland in Sydney's eastern suburbs last weekend encountered fences, 'No entry' signs and parking restrictions instead of the opportunity to enjoy the park's lakes, forests, lawns and animal life.

Part of Centennial Park's Brazilian Fields, a vast expanse of lawn with a pine forest backdrop, was cordoned off from the public for five days to provide a playground for employees of Atlassian and their families.

A Centennial Parklands spokesman would not reveal how much the software company, founded by billionaires Mike Cannon-Brookes and Scott Farquhar, paid to hire 2.4 hectares of parkland, claiming it was "commercial in confidence".

"Less than three per cent of the park was in use for the Atlassian event, the Peter Rabbit film set, and Moonlight Cinema, which remains open to the public outside cinema hours," he said.

Associate Professor Kurt Iveson, from Sydney University's Faculty of Science, said the hiring out of parkland was inequitable and undermined its purpose.

"There's growing pressure on operators of public spaces to 'recover costs', which introduces a logic of profit and loss into the provision of public spaces like parks – which are meant to be there for free public use," he said.

The hiring out of its grounds is a tidy earner for the Centennial Parklands, which has previously been accused of allowing a wealthy private school to buy exclusive access to its sports fields.

Fairfax Media understands the daily charge is about $20,000 to hire an area within the park.

Hiring out of The Domain, meanwhile, set back organisers of a two-week event $700,000.

Centennial Park charges a bond of up to $50,000 for events with more than 1000 people. Event organisers may also incur fees for turf restoration, which can cost up to $100,000, noise management ($5000 a night) and traffic control.

"All revenue from events and many other activities is invested back into the Parklands for the benefit of the community," the spokesman said.

Centennial Parklands had a reduction in government funding from $6.1 million in the 2015 financial year to $4.7 million in 2016.

The total amount of grants and contributions earned by the parklands in 2016 was $6 million – less than half the $12.3 million earned the previous year, according to its annual report.

However, it earned $10.3 million from the use of recreational facilities in 2015-16, compared to $9.2 million the previous year.

Professor Sue Holliday, from the University of NSW's Faculty of the Built Environment, said funding cuts had forced the parklands to find other revenue sources to pay for maintenance and development of the park.

"It is now rare for government to maintain parks with no 'co-payment' from contributions arising from the use of the park," she said. 

Up to 24 major events, which attract large visitor numbers, are permitted in Centennial Parklands each year - Moonlight Cinema, Polo in the City and JPMorgan Corporate Challenge were among events staged in the park in the 2016 financial year.

The spokesman said many of the events foster a sense of place and community. The Atlassian event had been the only private major event not open to the public in the current financial year.

"We acknowledge that it requires balance to manage all of the park's competing demands all of the time, due to the immense popularity of our valued spaces," he said.

Professor Holliday said long periods of "fencing" for events amounted to the privatisation and were, in her view, unacceptable. But filming and events like Open Air cinemas "are fine in my view".

Associate Professor Iveson said some events attract people who might not otherwise visit a park.

"But when those programmed events are expensive, and when they involve fencing off large chunks of public space for those who can afford to pay, then we start to see the public, non-commercial function of those spaces being undermined," he said.

Associate Professor Iveson said that commercial pressures could result in park areas being fenced off for longer periods. He also worries about the geographical consequences of parks being sustained by private funding.

"Parks should be available to everyone across the city," he said. "But if we rely on commercial activities to provide them, wealthy neighbourhoods and city centres have more capacity to raise money this way. If parks in those lower income suburbs have to rely on commercial activities to survive, they'll die."

Fairfax Media sought comment without success from Atlassian.