An accountant who killed himself after being questioned by police in the disappearance of two Hilton Head Island clients had embezzled $2.1 million from the couple and seven other companies, his former employer said Tuesday.

An audit ordered by management company The Club Group found that chief financial officer Dennis Gerwing took money from its clients for four years, depositing it into a hidden checking account, the company said.

Gerwing committed suicide March 11 after police questioned him about the disappearance of John and Elizabeth Calvert, a couple who live part-time on a yacht on the resort island and in a home in Atlanta. The couple were last seen in early March and searches of the resort island, its harbor and in Georgia have been fruitless.

Police have said Gerwing, 54, was the last person to see the couple together.

Mark King, president of The Club Group, said he met last week with the clients who lost money and promised to repay them using money from Gerwing's estate, insurance settlements and his own assets.

"I am still in shock over the betrayal of trust and the death of my partner of 21 years. I have no idea what might have prompted Dennis to engage in this behavior, but as chief executive, I want to apologize on behalf of our company to all who were adversely affected," King said in a statement.

Gerwing stole from eight of The Club Group's 10 Hilton Head Island clients by using wire transfers, checks and other transactions that mixed investment money with his personal funds, King said.

The Club Group has given authorities the findings of the audit, which was conducted by Baltimore-based FTI Consulting Inc., King said.

Tom Gardo, a spokesman for The Club Group, declined to specify how much money the company believes was taken from the Calverts or name any of the other companies from which Gerwing stole. He would not speculate whether the Calverts had discovered the theft.

A message left seeking comment from Gerwing's brother was not immediately returned.

The FBI will review the audit as part of its own investigation into the finances of Gerwing, the Calverts and The Club Group, Beaufort County Sheriff P.J. Tanner told The (Hilton Head) Island Packet.

The private audit can't be taken at face value, Tanner said.

"That's their opinion and that's what they put in their press release," the sheriff told the newspaper. "I can't support anything they put in there. It could be self-serving on their part or it could be what we find in the end. We're too far from this investigation being over to make that determination."

Investigators continue to go line-by-line over thousands of e-mails and check computers and cell phones in their search for the couple, Tanner said.

A message left for authorities after hours Tuesday by The Associated Press was not immediately returned.

The Calverts manage a marina and 125 rental units on Hilton Head Island. The Club Group kept the books for the Calverts' business holdings on the island. The couple decided in December to take their business away from the firm and manage it themselves. Gerwing was working out the details when the couple vanished March 3.