Planning Minister John Rau says he is frustrated that he can’t provide detail about what is planned for the development of more than 400 hectares of government land at Gillman.

Rau said today that he would be happy to talk more freely about the oil, gas and transport “hub” planned for Gillman under the deal – but Crown advice prevented him from doing so.

His argument is a change in tone from the defiant approach of Premier Jay Weatherill and Treasurer Tom Koutsantonis on the controversial Gillman deal, which provides exclusive rights to Adelaide Capital Partners (ACP) to develop the land.

ACP’s contract apparently involves the staged fill and development of parcels of the land over many years.

The Government insists the contract requires the eventual development of an “oil and gas hub” on the site, but details about exactly what this would entail have not been provided.

Rau was asked again about the deal on ABC 891’s breakfast program this morning and refused to say whether the oil and gas hub would be built during stage two of the contract.

“There is a contract between or a deed of agreement between the State Government and the ACP people,” he said. “That deed of agreement has various elements to it. Some of those elements – because they are elements that are sitting in the future – are elements that the agreement requires to be kept in a confidential state.

“My advice is that it is potentially a breach of our obligations under the deed of agreement for me to provide certain particulars about that part of the agreement.”

He said the deal was “complex” and involved a series of milestones.

“The first milestone was they had a certain period of time to complete certain preparatory works. At that point they then moved into the next phase and so on. I’m sure that there will be a point in time in the future before whenever the hub needs to be constructed when it will be fine for there to be more conversation about the detail.”

When asked if it was strange that the Government could not provide detail about its justification for inking the deal – the creation of jobs from the oil and gas hub – Rau said: “I’m just as perhaps frustrated by that state of affairs as you gentlemen are because I would be very happy were I advised and I’m at liberty to do so to have a conversation about that.”

The Government would not knowingly put itself in a position where it “could be in some sort of legal conflict with ACP”.

Opposition deputy leader Vickie Chapman called on the Government to release a redacted version of the contract.

“Snippets of the contract are being release by the Government and ACP on a highly selective basis, when it suits them,” she told InDaily.

“The contract should be released immediately to allow the public to decide whether or not the Government secured a good deal.

“Mr Rau is in charge of a department of lawyers – he should get a few of them to redact the commercially sensitive sections and release the rest.”

Also this morning, the former chief executive of the Department of Planning, Transport and Infrastructure, Rod Hook, said he had not been consulted about the Gillman deal.

Hook, who was axed by Weatherill last year, told the ABC the first he knew of the Gillman deal was when it became public in December 2013.

Hook wrote an opinion piece for InDaily this week which questioned whether the Government did its due diligence over the deal, and raising concerns about the impact of the controversy on private sector investment in South Australia.