Authorities searched Thursday for a prominent business couple last seen earlier this week at the Hilton Head Island yacht community they owned.

John and Elizabeth Calvert have a home in Atlanta and live part-time on a yacht docked at the gated Harbour Town Yacht Basin, which they own. Their management company also owns rental units and other businesses on the resort island, and Elizabeth Calvert is an attorney.

The couple was last seen Monday. Elizabeth Calvert's brother reported them missing on Tuesday after both missed work-related meetings, sheriff's Lt. Col. Neil Baxley said. One of their vehicles, a silver 2006 Mercedes, also is missing.

"This is suspicious because no one has had any contact with them in the past couple of days, which is in unlike the Calverts because they're active in the community," Beaufort County Sheriff P.J. Tanner told The (Hilton Head) Island Packet.

Deputies said they have not ruled out foul play. "We're checking every possible lead, talking to co-workers, friends, relatives, neighbors," Baxley said.

The Calverts' cell phones were either turned off or out of range and could not be used to help find them. Neighbors at their Atlanta home said they hadn't seen the couple there in about a week.

Deputies searched their yacht — Yellow Jacket — but found nothing to indicate where the Calverts may have gone, and their private plane was still at the airport, Baxley said.

Elizabeth Calvert, 45, specializes in employee benefits and executive compensation at HunterMaclean, said John Tatum, managing partner of the Savannah, Ga., law firm. She previously had been a corporate attorney for UPS in Atlanta.

"It's hard to think about anything else. We're all concerned about her," Tatum said.

In addition to running their management company, John Calvert, 47, is a member of the Hilton Head Marketing Partnership Alliance, which raises money for marketing the area.