The Age can reveal that the potentially toxic material is increasingly being dumped by members of the public, with more than 30 cases reported in the past 12 months alone.

The problem has become an "enormous frustration", according to Parks Victoria, which is already dealing with a stretched budget and other daily challenges such as feral animals, weeds and fire threats.

Incident reports also show that asbestos, which can be lethal if the fibre is disturbed, has recently been exposed in buildings at popular destinations such as Wilsons Promontory, Gabo Island Lighthouse, and Churchill Island.

"Illegal dumping of asbestos is a growing problem … and it requires significant funding to remove it safely – funding we could use for so many other purposes," said Chris Hardman, the executive director of Parks Victoria's Melbourne region.

"Because we don't know the origin, condition or breakdown of the materials, we need to engage qualified professionals to inspect the dumped materials each time they are discovered.  The safety of our staff and visitors is our first priority and clear procedures are in place to isolate and investigate materials wherever they are found."

Parks Victoria manages about 80 per cent of the coastline and 18 per cent of the state. However, the latest revelations are likely to put pressure on the Andrews government to tackle the problem, particularly after the agency's annual report showed its public funding has collapsed in recent years, from $122 million in 2011-12 to $97 million in 2015-16.

While Parks Victoria works closely with the Environment Protection Authority to investigate and prosecute offenders, it is understood illegal dumping has become so widespread that staff are struggling to keep up. Each clean-up can also cost anywhere between hundreds of dollars, to more than $9000 – courtesy of the taxpayer.

Opposition environment spokesman Brad Battin said tourism would suffer, particularly in regional Victoria, if Daniel Andrews allowed state-run parks to become "a wasteland" for dangerous materials.

"When it comes to our national and state parks it is the responsibility of government to ensure hikers, campers and international visitors are safe, the Andrews government has failed to address the issue, putting park users at risk," he said.

However, Environment Minister Lily D'Ambrosio blamed the former Coalition government, saying it "took an axe" to Parks Victoria funding, which had made illegal dumping of asbestos harder to detect.

"We're working to address the Liberals' neglect by giving Parks Victoria more resources to conserve park ecosystems and protect cultural heritage," she said.

The war of words comes as documents released to the state opposition under Freedom of Information laws found that between October 5 last year and March 31 this year, Parks Victoria recorded 326 occupational health and safety incidents, including:

* Exposure to asbestos at Churchill Island Marine National Park, the Lakes National Park, William Ricketts Sanctuary and the Wilsons Promontory Light Station.

* Attempted arson at Lysterfield Park on grand final Friday.

* Drunken bullying at a staff Christmas party at the Victoria Hotel in Dimboola.

* Contaminated water at the Warrandyte state park.

* The discovery of a body at Castlemaine Diggings National Park.

Asbestos was a popular building material before the health risks were widely known. While it is relatively safe when undisturbed, fibres that become airborne can lead to diseases such as lung cancer and mesothelioma. The government has urged anyone with information to contact Parks Victoria on 13 19 63.