Oranjestad, Aruba (CNN) -- A three-judge Aruban panel on Wednesday denied American Gary Giordano's appeal of a ruling keeping him behind bars for another 60 days as authorities investigate the disappearance of his American traveling companion, his attorney said.
Attorney Michael Lopez said Giordano was sad and disappointed with the ruling. Giordano is being detained improperly, he said, and his rights are being violated. Giordano left the hearing with a shirt covering his head.
On Tuesday, authorities on the Caribbean island questioned Giordano for an eighth time in connection with the disappearance of Robyn Gardner.
Gardner, 35, was last seen on August 2 near Baby Beach on the western tip of the island. Three days later, police took Giordano, 50, of Gaithersburg, Maryland, into custody.
Last week, an Aruban magistrate ruled that Giordano should be held for another 60 days while the investigation continues.
The magistrate's brief order did not elaborate on the decision beyond saying the suspect, identified by his initials of G.V.G., was "suspected of involvement in the possible drowning of the American woman," and that the custody extension "was done on request of the Prosecutor's Office."
Gardner has not been found; search efforts are ongoing.
The missing woman and the suspect arrived on the island July 31 from the United States, according to Aruban prosecutors.
Giordano told authorities he was snorkeling with Gardner and signaled to her to swim back, according to a statement from the prosecutor's office. When he reached the beach, Gardner was nowhere to be found, he allegedly said.
According to a transcript of a police interview, obtained by CNN, Giordano told police that he feared for his life when he signaled for Gardner to turn back and didn't look for her as he swam for shore.
"I only looked back when I hit a rock," the document quotes Giordano as telling investigators. "Before that, I did not look back. I was only busy saving my life."
Giordano has told authorities that he is the beneficiary of a $1.5 million accidental death insurance policy tied to Gardner, a local official told CNN.
Asked why Giordano called the insurance company about the policy less than two days after Gardner disappeared, Lopez said Wednesday he directed his client to make the call.
He said he believed Giordano's continued detention stems from the high-profile case of Natalee Holloway, an Alabama teenager who disappeared on Aruba in 2005 and has never been found.