But rather than trumpet the rediscovery, staff within the Office of Environment & Heritage were told to keep the finding a secret until the SIMTA project won approval - which it did from the Planning Assessment Commission (PAC) on December 12 last year. "They wanted to keep it quiet," one insider told Fairfax Media. "They didn't want anything to complicate things." The person, who requested anonymity, said staff are afraid to speak out: "We are all under pressure not to rock the boat – so many of us have already lost our jobs." Mark Speakman, the environment minister until the appointment of Gladys Berejiklian as the state's new premier this week, said he was unaware of the flower's status. "Neither I nor my office gave, or was aware of any, direction about dealing with any discovery of hibbertia fumana at the Moorebank site," he said.

No mention An OEH spokesman said it was not his department's role to inform PAC of the fumana's rediscovery. Despite the federal demand for a study, the PAC report made no mention of hibbertia. The plant was granted a "critically endangered" emergency listing by the NSW Scientific Committee four days after the PAC ruling. "This area of bushland where the plants have been found is proposed to be set aside as a biobanking site as part of the adjacent development," the OEH spokesman said.

"The species has only been found on the proposed biobanking site and not in the development footprint," he said, adding the government is working with the alliance behind and the commonwealth "to ensure the security of the plants". A spokesman for SIMTA dismissed a claim the proposed development would run through some of the hibbertia plants. He released this chart showing the plants falling within a proposed conservation area: Wayne Olling, secretary of the Cumberland Conservation Network, said the government should allow outside groups such as his own onto the site to confirm the plants would indeed be secure. "Here's an opportunity to save a species that we thought was lost and now found," Olling said. "The NSW government should have informed the PAC that there was a significant finding."

"Given all the concealment that's taken place so far, we have no confidence in what they say," Olling said. 'Very dodgy' Labor, the Greens and the NSW Nature Conservation Council (NCC), said the project needs to be reviewed after the finding of the rare plant. "Any attempt to withhold information during the planning process is a very serious matter," said Penny Sharpe, Labor's environment spokeswoman, adding Minister Speakman "must publicly guarantee that there has not been any interference in the planning process either directed by his office or his department". Mehreen Faruqi, the Greens environment spokeswoman, said there was "something very dodgy" about this whole thing.

"We need to know who knew what and when as well as how the project was approved just a few days before this critically endangered species was listed," Faruqi said. "The environment minister needs to press pause and understand that this species occurs only on this site and if it is bulldozed, then it is likely gone from this earth forever." Kate Smolski, chief executive of the NCC, said it was unacceptable the federal government approved projects before the full environmental impacts are known, and a stop-work should now be imposed on the project. The process also revealed "systemic failures" on the part of the NSW planning system, she said. "The government should also explain why it took until mid-December to list the species as critically endangered when it was rediscovered on the site more than a month earlier," Ms Smolski said.

"It is hard to avoid the conclusion the NSW government delayed listing the species to ensure the project went ahead as scheduled." No review Fairfax Media sought comment from Josh Frydenberg, Mr Hunt's successor in Canberra. The federal environment department, though, echoed comments of its state counterparts, saying that no fumana plants lie within the development site. An offset site is being prepared so that the fumana "are not impacted by the project and will be protected in perpetuity", the department said in a statement.

Since the plant was not listed - as it as was thought to be extinct - its discovery "will not trigger any review of the project's approval", the government said. "[N]ew species listings do not affect pre-existing approvals." ​Follow Peter Hannam on Twitter and Facebook.