HONOLULU -- The embattled deputy state transportation director in charge of airports abruptly stepped down last week with just five days’ notice.

Brian Sekiguchi's management skills and ethics have come under fire by a key state senator.

For the last seven years, Sekiguchi oversaw 15 airports in the state, with a multimillion dollar budget and hundreds of employees. Sekiguchi was paid about $100,000 a year.

He's been under fire for a number of questionable business deals by the airports division, which is paying more than a $500,000 a year to sublease this building on Ualena Street near Honolulu Airport that it already owns.

The state is paying twice as much money to buy half the land it had planned to purchase to expand the heliport at Lihue Airport on Kauai.

At a July 19 hearing, State Senate Ways and Means Chairwoman Donna Mercado Kim accused Sekiguchi of taking at least one day of vacation in April of 2009 without putting in for vacation time.

"I was on vacation, but I did meet with airline officials while I was on the mainland. And that's something that we try to do sometimes to kill two birds with one stone," Sekiguchi told Kim’s committee at the hearing.

His vacation leave form shows just one approved day off: April 9, 2009. However, he admitted he left town the morning before, on April 8. Then Kim asked Sekiguchi if he accepted free tickets from an airport vendor for part of his vacation -- to the Augusta, Ga., The Masters golf tournament:

Sekiguchi: "That is incorrect. I was on personal vacation ... Uh ..."

Kim: "So one of the airport vendors didn't pay for your tickets to go to The Masters?"

"No they did not," Sekiguchi said.

"So you paid for your own ticket to the Masters?" Mercado asked.

"Yes, I did," Sekiguchi said.

His gift disclosure form shows no gifts from that time period.

Kim said she was not convinced he told the truth.

"There seems to be some improprieties going on regarding your position and regarding vendors that you have control over," she said.

His boss, Transportation Director Brennon Morioka said, "We at the department, as well as this administration, takes those kinds of things very seriously, as well as the perception."

On Monday, Morioka's spokeswoman would only say Sekiguchi offered his resignation and the DOT accepted it as of Friday, five days after he announced he was quitting.

Gov. Linda Lingle’s spokesman said she did not ask Sekiguchi to step down, and he did not give her a reason for his resignation.

KITV4 News left a message at Sekiguchi's home on Monday and with his former secretary at the Department of Transportation to try to get in touch with him, but he did not return the phone calls.

Kim has been critical of the Lingle administration for creating a civil service airports administrator position that had not been authorized or funded by the Legislature. Kim claimed the job requirements were written in such a way as to give Sekiguchi an advantage in getting the job, which would have allowed him to remain working for the state after the Lingle administration and other political appointees leave office at the end of the year.

Several other recent incidents have raised questions about the management of the airports division, which Sekiguchi oversaw.

On Friday, KITV4 News reported a business services supervisor at Kauai’s Lihue Airport admitted to stealing about $13,000 over at least four months before being discovered in July. The woman is on administrative leave while the state attorney general’s office probes the case.

State DOT Director Brennon Morioka said the state is looking at its internal controls and protocols to prevent similar schemes in the future.

Even though Lihue Airport handles far fewer passengers and flights than Kahului and Honolulu airports, it was the only airport in Hawaii to pay security fines to the Transportation Security Administration for security lapses between March 2009 and March of this year. Lihue Airport paid the TSA $75,000 for 15 different security incidents, according to state DOT records.

On July 27, state Procurement Office administrator Aaron Fujioka found the state Department of Transportation violated procurement law when it hired two airport security consultants through Securitas Security Services USA, an airport security contractor.

The state Airports Division of the DOT has been the subject of an ongoing probe by Kim’s Senate committee for more than a year. Her investigation revealed:

The Airports Division is paying more than $500,000 a year to sublease its own building on Ualena Street near Honolulu International Airport.

The state is paying twice as much money to buy half the amount of land it had planned to purchase to expand the heliport area next to Lihue Airport on Kauai.

A $1.5 million contract approved in 2000 for a high-tech sensor system to monitor taxis at Honolulu International Airport was supposed to take less than three years to complete, but the project dragged on for nine years before being finished.

Parking contracts at neighbor island airports have been on a month-to-month basis for at least seven years.

The state is failing to charge tenants at Lihue Airport $16,000 a month in solar power system costs.

Sekiguchi, who lives in Aiea, has been the deputy transportation director for airports since 2003. Before that, he spent 22 years in the military construction and engineering field at both the U.S. Navy and the U.S. Air Force.

At the time of his state appointment seven years ago, he was resident officer in charge of construction for the Naval Facilities Engineering Command at Pearl Harbor. At that time, according to a news release from the governor’s office, he oversaw 650 projects including construction and environmental work.