A registered lobbyist at the Iowa legislature has been arrested, accused of threatening to extort $1 million from the conservative Iowans for Tax Relief, authorities said today.

Mary Katheryn Moravek, 51, of Mechanicsville, Iowa, was charged Tuesday with extortion, a Class D felony.

The Muscatine County Attorney's office said Moravek tried to extort money from the group and its chairman, David Stanley.

The release did not indicate what wrongdoing was being alleged, and an assistant county attorney declined to be more specific.

Ed Failor Jr., president of Iowans for Tax Relief, said today, "All I can tell you is somebody did try to extort our organization, and we turned it over to the authorities."

Alan Ostergren, an assistant Muscatine County Attorney, said contact in the incident was first made on Monday.

Stanley talked with Moravek on the telephone this morning, and she agreed to accept "$30,000 in lieu of making false allegations of wrongful conduct," according to the county attorney's office.

Two Iowans for Tax Relief employees were to meet with Moravek, authorities say. Instead, an undercover sheriff's detective arrested her about 1 p.m.

Moravek was being held in the county jail while awaiting an initial appearance before a judge.

Ostergren said that wouldn't happen until Wednesday.

"She was threatening to accuse them of all sorts of things that were false and demand payment not to make those accusations," Ostergren said today.

He added he didn't think there was any political motive behind the attempt.

"I think it was more personal for her," he said.

Moravek was registered as a lobbyist for the Iowa Commission of Persons with Disabilities during this year's legislative session, according to the legislature's Web site.

She also is listed as being a member of the organization's board. The Web site said she was appointed to a two-year term last July.

The penalty for a conviction on a charge of extortion is up to five years in prison and a $7,500 fine.