When people think of big money being spent at Fort Lauderdale-Hollywood International Airport, they usually think of the new runway and other construction projects -- not janitorial service.

But cleaning the airport is a million-dollar-a-month business that is currently being done by Broward-based Sunshine Cleaning, which has also had lucrative contracts to clean county hall and the main library among other government buildings.

That airport contract is now under investigation by the Broward Office of Inspector General.

Sunshine at one point was doing $22 million a year in public projects making it Broward County's largest non-construction vendor, said Broward County Auditor Evan Lukic.

Lukic released an audit of the company's $12 million annual airport contract last year and found that the county had paid Sunshine $950,000 more than required for labor in one year due to lopsided contractual obligations. The audit also found that Sunshine had overbilled the county some $15,000 during two months reviewed.

But one of the most troubling findings was that air-traveling taxpayers in Broward were paying about twice as much per square foot for cleaning the airport as their counterparts in Palm Beach and Dade counties.

The Inspector General's investigation is focused on Sunshine's requirement to share the airport contract with small businesses to help spur economic growth. One small company hired as a subcontractor by Sunshine is Emily K. Evans Cleaning Service. 

Sunshine claims in official reports to have paid Evans' firm some $9 million during the past three and half years (along with millions more for her help with other government contracts). But Lukic's audit found that all the airport contract's employees were paid directly by Sunshine, not by Evans or any other subcontractor.

"The question becomes how much money did [Evans] actually receive and what did the county receive in return for those services?" says Lukic.

When I caught up with Evans, she hid her face from the camera and refused to answer any questions about her work with Sunshine. Sunshine owner Larry Calufetti, a political campaign contributor who has lobbyists George Platt and Bernie Friedman working for him, also refused an interview.

Calufetti's company released a statement saying the company never misspent any county money. From the statement: "[Evans] directly manages six supervisors and 75 cleaners. She has 20% of the cleaning contract at the airport. It was also confirmed that the Evans company was paid every two weeks for its services at FLL. and that Evans did supervise 20 percent of the contract and was paid for doing that work."

The company also claims that Lukic's analysis on the cost of the airport contract was flawed and notes that it was low bidder for the contract back in 2008. Again from the statement: "We are proud to say that the Ft Lauderdale airport, one of the busiest in the country, is also one of the cleanest. This has been accomplished by the Sunshine and its small business partners working closely with the Broward County Aviation Department on a 24-7 daily basis."