The State Law Enforcement Division has launched an investigation into the Charleston County Aviation Authority after the former director suddenly resigned in July, SLED confirmed Monday.

“We received a request, and we are conducting an investigation,” SLED spokesman Thom Berry said.

He declined to detail the specifics of the probe, but Aviation Authority Chairman Andy Savage said he forwarded the resignation letter of outgoing Airports Director Sue Stevens to SLED.

“I provided them with the allegations that she made,” said Savage, who added that he had been contacted by SLED to confirm that the probe was underway.

In her five-page letter of resignation July 23, obtained by The Post and Courier in August after the Aviation Authority refused to release it, Stevens wrote, “After one board meeting, I found a check for $1,000 made payable to his (former Aviation Authority chairman Chip Limehouse’s) campaign fund in a folder along with a company brochure providing information about the construction management firm. The board later voted to give work to this particular company.”

She did not name the firm that wrote the check or say when the incident occurred.

Limehouse, who remains a member of the airport board but since January has sent a proxy to represent him at meetings, said Monday he wasn’t aware of the investigation and has not been contacted by SLED. He said he isn’t sure who made the contribution to his campaign but that it is not unusual for him to receive donations all the time.

“Even if it was a contractor, a person is entitled to make a campaign contribution,” he said. “There has to be a quid pro quo (somebody getting something in return for the donation for it to be illegal). To my knowledge, no one at the airport ever took any contributions from anybody related to receiving a contract. That’s just totally fabricated, totally made up, totally untrue. She makes all of these allegations all the time and never puts any specifics behind them. It’s hard to respond when you don’t know what she is talking about.”

Limehouse said the check wound up in a folder at the airport because he had it in his coat pocket, then stuck it in the folder.

He couldn’t say when it was handed to him, whether at an airport board meeting or before he got there.

“What difference does that make?” he said. “At the end of the day, the investigation is not going to find any wrongdoing with any airport officials, past or present. It’s much ado about nothing.”

Stevens also alleged in her letter that a former airport board member received a contract to perform management services for the firm overseeing the $189 million overhaul of Charleston International Airport, then left his partnership with that firm so he could start bidding on construction projects related to the terminal makeover.

She did not name the former board member.

“When I have objected to these improper and unethical actions, I have been treated rudely and condescendingly in public,” she wrote.

At one point, she said Limehouse told her that if she couldn’t handle the job he would find someone who could.

The rest of Stevens’ resignation letter dealt with her accomplishments over the past 26 years as an employee of the Aviation Authority and director since 2006, and her perceived ill treatment by some board members who she said asked for job favors for friends and relatives.

Stevens’ attorney, Nancy Bloodgood, confirmed Monday that SLED contacted Stevens last week but that the former director would not be able to meet with them until after Oct. 7 because she is out of town.

Limehouse claims Stevens grew disgruntled last year when he spurned her request for a raise and a contract because he believes public employees should serve at will.

In Stevens’ letter, she is seeking “a fair severance” or is threatening legal action against the all-male board, some of whom she said belittled her because she is a woman.

“It’s in her interests to stir up as much trouble as she can,” Limehouse said Monday. “If she can muddy up airport officials enough, she can scare them into giving her a severance package. I hope they don’t fall for it.”

After Stevens stepped down from her $211,000-a-year job directing Charleston County’s three airports, the 13-member airport board voted 8-5 in August to give the job to state Sen. Paul Campbell, a Goose Creek Republican and former Alcoa executive. He is being paid $192,000 a year.

Stevens is on paid leave until Monday. Bloodgood said she has not been contacted by airport officials about a proposed settlement, and that Stevens will make the final decision on whether to go forward with a lawsuit if a severance package is not offered.

“I hope it doesn’t come to that,” Campbell said. He added that Aviation Authority staff has not been contacted by SLED.

Reach Warren L. Wise at 937-5524 or twitter.com/warrenlancewise.