A U.S. senator is confident that new CIA evidence could solve the mystery of what happened to Gulf War Navy pilot Michael Scott Speicher (search), shot down over Iraq more than 12 years ago.

Sen. Bill Nelson (search), D-Fla., a member of the U.S. Armed Services Committee, said he was optimistic about discovering Speicher's fate.

"The clues would suggest that there are new leads. [The CIA is] following those right now from a multiplicity of sources," he said.

Speicher's plane was downed by an anti-aircraft missile the first night of the 1991 Persian Gulf War. The Pentagon declared several months later that he had been killed in action, but last year revised his status to "missing in action, captured."

In April, investigators moving with U.S. forces through Iraq found Speicher's initials — "MSS" — etched into a wall in the Hakmiyah prison in Baghdad. An informant at the time said an American pilot was held at the prison in the mid-1990s.

At a press conference in Kuwait City late Monday, Nelson said he visited the "hell-hole prison cell," as well as a torture chamber in the prison.

"In the basement, we saw the place where the torture took place. We saw where the chair that the prisoners would be strapped into was ripped from the concrete floor. We saw the wires and the holes that the wires came out for the electrical shocks," he said.

Nelson added that other information regarding Speicher is classified, but possibly useful.

The Speicher family's lawyer, Cindy Laquidara, told Fox News on Tuesday that she had information consistent with allegations that Speicher was held in a cell for a number of years, but, again, that the information was highly classified.

"There is new evidence and it's good evidence. It is favorable evidence, it is now again, yet again, another piece that Scott was alive and in captivity, and in captivity until very recently," Laquidara said.

She added that the information pointed to specific locations, and that there is hope that Speicher is still alive.

Nelson added that he is very frustrated by how long it is taking to get DNA results back from a strand of hair that was found in the Baghdad cell where the initials were carved. The DNA sample was taken back in April, but as of yet, no official results are available.

Lt. Cmdr. Speicher, an F/A-18 Hornet pilot from Jacksonville, Fla., and three other pilots flew off the USS Saratoga (search) for a bombing run over Iraq on Jan. 17, 1991. During the mission, another Hornet pilot saw a flash and lost sight of Speicher's craft.

The next morning, the Defense Department announced that Speicher's plane had been downed by an Iraqi missile. Several months later, the Pentagon classified Speicher as killed in action.

Iraqi officials maintained that Speicher was killed in the crash, but U.S. officials said intelligence reports led them to change his official status.

Speicher, who was 33 when he went missing, left behind a wife, a 3-year-old daughter and a 1-year-old son. His wife, Joanne, has since remarried.