Aruba ? The father of a U.S. teen who went missing nearly four years ago in Aruba said Sunday that a private investigator will scour a retention pond for answers that have eluded the family throughout numerous false leads and fruitless searches.

Dave Holloway said tracker dog specialist Fred Golba, from Chicopee, Mass., will begin his latest search for evidence into Natalee Holloway’s May 2005 disappearance early today. He said the tracker, who has searched for her eight times before, must be accompanied to the pond by Aruban police escorts, who delayed an anticipated weekend search.

Natalee Holloway, from Mountain Brook, Alabama, was 18 when she was last seen leaving a bar in the Aruban capital on the final night of a high school graduation trip.