Investigators are searching computers, cell phones and personal digital devices to try to find out what happened to a missing Hilton Head couple.

Beaufort County Sheriff P.J. Tanner tells The Island Packet newspaper that detectives are going line-by-line through thousands of e-mails and other information. Tanner's comments were the first update on the investigation in three weeks.

Tanner says the items belong to John and Elizabeth Calvert and Dennis Gerwing, the businessman who was named a person of interest in the case. Authorities say Gerwing, who committed suicide, was the last known person to see the couple.

The Calverts' yacht, The Yellow Jacket, is moored near the Harbour Town golf course's 18th green, where thousands of tourists are attending the Verizon Heritage tournament.

The yacht is covered by a large, black tarp.