The 50-year-old creep remains prime suspect in the case but with no body and little evidence they are being forced to let him go.
But Aruban Solicitor General Taco Stein, who has previously called Giordano a "mean bastard" said that he could still be extradited if they gain enough evidence.
He told NBC Washington: "We feel that a crime has been committed. We still see Mr. Giordano as the main suspect in that."
"As long as we don't have the body or we don't have trace evidence or we don't have the material to bring us to a conclusion on that, it's very difficult to make a charge.
"The only thing at this point in time you can say is she went missing on the second of August and we presume she's dead but we don't have evidence to that effect."
Investigators suspect Giordano because he tried to cash in a huge travel insurance policy he'd taken out on Gardner shortly before they left.
They added that there were inconsistencies in his story.
It's thought that he will return to his home in Frederick MD, when he's released this week.