Three weeks after the head of a state environmental oversight group was fired, the mystery of what led to her sudden dismissal remains.

But there is plenty of finger-pointing as the mini-drama at the State Capitol continues to unfold.

Susan Thornton's last day as director of the Legislative-Citizen Commission on Minnesota Resources is Tuesday, but her attorney maintains that those responsible for the firing -- including House Speaker Kurt Zellers -- had no authority to remove her.

The panel's next meeting, which was also scheduled for Tuesday and was seen as an opportunity to air the issue, has been abruptly canceled. Nancy Gibson, the commission's co-chair, charged that Republicans who initially cast Thornton's firing as part of a move to change direction are engaged in a "covert operation." In an e-mail this week, Gibson said that canceling the meeting meant she and others were "being asked to acquiesce to this coverup of public-policy without any discussion."

Rep. Tom Hackbarth, R-Cedar, the panel's other co-chair, said he asked for the cancellation because of unrelated scheduling conflicts. On Wednesday, he said of Gibson: "I don't know what kind of black helicopters Nancy Gibson is seeing. There's been absolutely no coverup of anything whatsoever. This is an internal matter."

Gibson said the controversy may in part be driven by influential outdoors groups that are upset with Thornton about decisions over funding and oversight, but a House Republican spokeswoman said legislators simply wanted the panel's money going to "more on-the- ground conservation and habitat projects" such as aquatic invasive species issues and chronic wasting disease.

For much of its existence, the 17-member panel has existed in relative anonymity, making recommendations on who should get money for environmental and natural resource projects. Many of the dollars come from a trust fund that gets money from the state lottery and investment income, and since 1963 the panel has recommended how more than $735 million should be spent.

That changed last month when Thornton, who had served as director since 2008, was fired. Her attorney, Vince Louwagie, said only the Citizen Commission could fire Thornton, since it had hired her. He said the Legislative Coordinating Commission, the panel that actually fired Thornton and that was chaired by Zellers, had overstepped its legal authority.

"I've not heard anything that tells me what authority they think they have," Louwagie said.

Greg Hubinger, the director of the Legislative Coordinating Commission, which exists to "coordinate legislative activities," said the panel has hired a $250-an-hour lawyer to represent it against Thornton. The lawyer, Amy Schwartz, said she would not comment. "I really don't have any prediction as to what will happen," she said.

Jodi Boyne, a House Republican spokesperson, said Zellers was not involved in canceling Tuesday's meeting.

Joining the fray, House Minority Leader Paul Thissen said Wednesday that he too wants answers to Thornton's "unilateral dismissal." Thissen, a DFL member of the Legislative Coordinating Commission, said the upcoming meeting should be held as scheduled to "transparently address the questions and concerns" raised by Thornton's firing.

Mike Kaszuba • 651-222-1673