JACKSONVILLE, Fla. -- A well-known businessman whose company is being investigated by the FBI is taking a voluntary leave of absence from his board position with the Jacksonville Port Authority.

Tony Nelson is the founder and president of Muirfield Partners, an engineering and management service. Last week, federal agents raided the offices of Muirfield in the 8700 block of San Jose Boulevard, as well as the First Coast Black Business Investment Corp.

The FBI has not said the nature of their investigation or what they were looking for at his offices, but they seized documents that have to do with contracts with the port.

The FBI also raided two not affiliated with Nelson: Subaqueous Services Inc., a dredging company, and Rham Construction. Both have done business with the port.

In a letter to Mayor John Peyton, Tony Nelson wrote:

"In light of recent public issues, and my loyalty to the best interests of the City of Jacksonville, the Port and the mission of creating jobs and developing new commerce for the city of Jacksonville and Northeast Florida, I believe it serves everyone that I take a leave of absence until these issues are satisfactorily resolved."

Nelson's board position at Jaxport is unpaid.