The last person believed to have seen a missing part-time Atlanta couple embezzled more than $2 million from them and other clients, according to an accounting firm.

Dennis Gerwing, who killed himself the day he was named a person of interest in the disappearance of John and Liz Calvert, misappropriated $2.1 million of The Club Group's money over four years, according to Baltimore-based FTI Consulting.

Dennis Gerwing killed himself the day he was named a person of interest in the disappearance of John and Liz Calvert.

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Gerwing was chief financial officer of The Club Group, which handled finances for the Calverts' Hilton Head Island, S.C., yachting and resort rental businesses.

Gerwing used secret checking accounts, bank teller transactions and wire transfers to cover up the scheme, according to the audit.

"I am still in shock over the betrayal of trust and the death of my partner of 21 years," Club Group president Mark King said in a statement. "I have no idea what might have prompted Dennis to behave in this behavior."

The Club Group is working to repay money to its clients, the statement said. It was not clear how much money Gerwing embezzled from the Calverts.

Until their March 3 disappearance, John, 47, and Elizabeth, 45, maintained a home in Brookhaven, but spent much of their time on their yacht – the Yellow Jacket – on Hilton Head.

Beaufort County, S.C., sheriff's investigators found their 2006 Mercedes on the island three days later. Searches of the car, their boat, a wildlife refuge, the Atlantic Ocean and a Georgia landfill turned up no obvious signs of their whereabouts.

"In some ways, it's like looking for a needle in the haystack," Beaufort County Sheriff P.J. Tanner told the Island Packet newspaper Tuesday. Phone calls and e-mail to the sheriff's office were not immediately returned Wednesday morning.