Robyn Gardner was groggy from sleeping pills, vodka and a meal when she went into the water in Aruba where she quickly cut her toe, forcing her out of the water, a source told ABC News.
But the 35-year-old Maryland woman ventured back into the water a second time, and that was when she was allegedly caught by treacherous currents, her companion Gary Giordano has told police, the source said.
Giordano's version of events emerged as doubt has been cast by witnesses in recent days that Gardner ever went into the water. A witness at the restaurant where the couple were last seen together expressed surprise at the claim that Gardner went snorkeling because of the obvious effort she had put into her hair and make-up that evening.
A second witness claims to have seen the couple stroll on the beach, but not enter the water.
Source Insists Robyn Gardner Did Go Swimming Day She Disappeared
Giordano, 50, is being held in an Aruban jail and is the lone suspect in Gardner's disappearance, although he has not been charged with a crime. Aruban police have said they believe Gardner is dead.
Giordano has previously stated that Gardner had taken sleeping pills earlier that day and the two drank vodka at the Marriott Hotel before showing up at the Rum Reef Bar & Grill in the Baby Beach area of the island on the Aug. 2 evening that she vanished.
People at the beachfront restaurant said she was woozy and barely ate her salad.
But the source said that she did go in the water, gashing her toe on her first attempt to go swimming. She retreated with her toe bleeding, and a spot of blood was found near where the couple's rental car had been parked, the source said. Forensics is still testing the blood.
The source also said that helicopters spotted two sharks and a giant sea turtle in the area about the same time that Gardner vanished.
Gardner's live-in boyfriend Robert Forester scoffed at the latest claims, telling "Good Morning America" that Gardner was not the type to go snorkeling because it would mess up her hair and make-up, or to take sleeping pills.
"I've never known Robyn to take any sleeping pills in the middle of day, nor do I know why anybody would take sleeping pills during the middle of the day," Forester said.
"But let's go with his word here," Forester said of Giordano. "So you say she was taking sleeping pills, then you give her vodka? And then you take her snorkeling? Really? Why would anybody do that?"
"Obviously I don't believe anything he's saying," Forester said.
Investigators are also looking into Giordano's claim that Gardner took out a travel insurance policy for up to $1.5 million before the Aruba getaway and named Giordano the beneficiary of the policy.
The ABC News source says a witness was present when Gardner named Giordano as the beneficiary on the travel insurance policy, and that Gardner was fully coherent when she signed it.
Forester said that he is upset that the woman he was considering marrying was off an island tryst with another man.
"Am I angry that she was there with him? Of course. Do I ask myself why and what she was thinking? Yes," said Forester. "But I can't let that consume me. What does consume me is what we can we do to find her. What I'd like to see as soon as possible is a search with canines."
The last contact Forester had with Gardner, his girlfriend of more than two years, was a message from her around 3 p.m. on Aug. 2, saying, in part, "I love you, I care about you, we'll talk and sort this out when I get back."
The ABC News source says that message was sent with the intention of ending the relationship when she returned to Maryland, something Forester also disputes.
"Part of that message to me, prior to that, was, 'this sucks.' So I highly doubt that's what it was," Forester told "GMA." "Not to mention that our plan for the weekend she came home from the trip was to find an apartment together."
Photos taken of Gardner and Giordano just before she disappeared were obtained by ABC News Tuesday. They show her leaving the restaurant with Giordano. She is wearing a long dress that Forester said was her favorite dress.
The time stamp on the photo is 4:12 p.m. on Aug. 2. Surveillance video shows Giordano back at the restaurant at 6:02 p.m., trying to alert people that Gardner had vanished.