Even as she contends with state criminal charges, Pennsylvania Attorney General Kathleen G. Kane is also facing scrutiny by the FBI, The Inquirer has learned.

In recent months, agents have questioned at least three people about several issues, including Kane's role in negotiating a new contract with the union representing narcotics agents in her office, according to people familiar with the matter.

The agents sought information about whether Kane suggested to union officials that she would look favorably on their contract if they supported her embattled chief of staff, sources said.

Investigators have also sought information about a trip Kane and several aides took to Haiti last year, and how it was paid for, according to the sources.

The scope and intensity of the federal inquiry are unclear, but it comes as Kane prepares to mount a legal fight against criminal charges that she leaked confidential material to embarrass a critic, and then lied about it under oath. A preliminary hearing in the case, filed in Montgomery County, is scheduled for Monday.

A spokesman for the FBI in Philadelphia declined to comment Wednesday.

Kane's lawyer, Gerald Shargel, could not be reached for comment.

Her spokesman, Chuck Ardo, said the office was unaware of a federal inquiry.

He said he had no knowledge of Kane's discussions with Lodge 74 of the Fraternal Order of Police, which represents about 100 narcotics agents in the Attorney General's Office.

"I don't know anything about that," he said.

Sources familiar with Kane's negotiations with the union said they occurred in April, shortly after she promoted Jonathan Duecker to be her chief of staff.

Duecker was a controversial selection. Almost immediately, reports surfaced that two women in the Attorney General's Office - a narcotics agent and a prosecutor - had told their supervisors that Duecker had made unwanted sexual advances to them. As The Inquirer has reported, Kane knew about the allegations before promoting him to the top post.

During a session with the FOP's lawyers, Kane said she wanted Duecker to remain in the job, according to people briefed on the exchange. She asked if the union would be willing to support her new chief of staff, and suggested that if it did, she would look favorably upon its new contract, the sources said.

A month later, the board of the FOP, which represents one of the women who brought a complaint against Duecker, rejected Kane's request for a letter of support for him, according to two people familiar with the union's decision.

The FOP contract expired June 30 and its members have been working under the terms of their previous pact.

Melissa Murphy Weber, one of the lawyers representing the FOP, declined to comment Wednesday. Lawrence Moran Jr., another FOP lawyer at the time of the negotiations, did not return calls.

The union's president, Chris Juba, also declined to comment.

Duecker remains Kane's chief of staff, despite a recommendation this spring from the attorney general's human resources office that he be fired.

As for the little-publicized Haiti trip in April of last year, Ardo described it as a week devoted to charity. He said Kane and four staffers who accompanied her paid their own expenses and went there on their own time because the trip was not official business.

Among other things, he said, Kane and her aides visited a shelter for women who had been sexually abused.

In recent weeks, FBI agents have asked about the trip and how it was paid for, sources said.

Ardo said four of Kane's staffers joined her: David Peifer, a top commander of the office's agents; Kane's twin sister, Ellen Granahan, a deputy state attorney general who heads a unit that pursues child predators; Dan Block, a supervisory special agent; and Justin Leri, a special agent who works in the child predator unit.

In charging Kane this month, prosecutors said she had conspired with Peifer and Patrick Reese, the head of her security detail, to spy illegally on her employees. The object was to learn if the employees were cooperating with a grand jury investigation of Kane, prosecutors said.

Only Reese was charged in the case along with Kane, suggesting that prosecutors may be attempting to persuade Peifer to join their side as a cooperating witness.

Asked about the Haiti trip in an interview this year, Kane said she was inspired to go to the tropical island by her youngest son. She said he showed her a video about a campaign to raise awareness and money after an earthquake killed 220,000 people there in 2010.

Kane said that she did not take her son with her because it was too dangerous and that she had guards with her.

Kane said she visited four or five orphanages in Haiti, bringing them cash, shoes, toys, and dental supplies.

"You see these kids who live in mud huts and just a village that has nothing," Kane said. "They have the one horse tied up to the tree. But yet these people, what I love about it is, these people have hope - that you would think, how do they have hope through all this? But they do. You really see the spirit of some people burn through. It's amazing."