On Friday, solicitors for the Save Killalea Coalition wrote to Minister for Lands Tony Kelly questioning how the company could list the site as an asset.

"As you would be aware, an agreement to lease is not a proprietary interest - unlike a lease," the letter, signed by Environmental Defender's Office solicitor Kirsty Ruddock, reads.

"Also, the final lease of the area is dependent on a development consent being granted.

"We understand from recent correspondence that no such consent exists ...

"We trust in the circumstances that you will urgently seek to clarify publicly that there is no agreement to lease so that the market and potential purchasers are clear that what they are purchasing is no more than a speculative investment in an agreement to lease with no legal rights to the land itself."

The letter claims that the market announcement confirms private leasing arrangements relating to the park were being made behind closed doors.

It asks that lease arrangements are not made before the public is able to comment on their appropriateness.

South Coast Labour Council secretary Arthur Rorris said he wanted clarity on how Killalea was being represented.

"Are they saying that that's their land to sell? Because if they are then it makes a mockery of Minister Kelly's assertion to the people of the Illawarra that there's no intention to sell this land," he said.

The Killalea State Park Trust has a development agreement with Killalea Coastal Investments, which was initially a joint venture between Mariner Financial and Babcock & Brown.

The latter was placed in external administration in March, and Mariner took over the venture.