A secret Pentagon report says the Iraqi defector who claims to have seen Navy pilot Michael Scott Speicher (search) alive years after his disappearance has been called a "born liar," a Washington newspaper reported Wednesday.

The Washington Times, getting a copy of the classified Pentagon document, reported that an Iraqi interviewed by U.S. investigators characterized defector number 2314, the source of the story, as a "born liar."

According to the paper, the Pentagon document reads: "None of the information provided by 2314 has proven accurate." Military officials told Fox News that the defector has been deemed unreliable.

The document, which dates to June 23 of this year, also blows a hole in 2314's story about seeing Speicher in 1998 and others who may have seen Speicher. The defector named several people whom he said knew where Speicher was. Each one has denied the knowledge, according to the Pentagon paper.

The Pentagon report has surfaced just as public officials had said that the search for Speicher was making progress. A senator close to the investigation told Fox News that he thinks the mystery of Speicher's whereabouts may soon be solved with the help of lower level Iraqi officials.

"Once all of that is coordinated with the documentation and the locations that we are looking at, then I think we are going to get the final conclusive evidence," said Sen. Bill Nelson (search), D-Fla.

Military officials also told Fox News that they are still looking into other evidence, for instance, a book that was found at the prison that listed details in Arabic about several prisoners of war.

Sources confirmed to Fox News that Speicher's name was listed in the book. Sources inside the Pentagon then said that while the book, dated January of this year, is being translated, officials are trying to track down Iraqis listed in the book who can be questioned about Speicher's fate or whereabouts.

Speicher's F-18 was shot down over Iraq on the first day of Operation Desert Storm (search) in January 1991.

He was originally classified as "killed in action," but last year his status was revised to "missing in action, captured." Military officials said his status was changed because they couldn't find any evidence Speicher had been killed in the crash.

Nelson said that he has hopes that Speicher's whereabouts will be known.

"I have been very pessimistic for the last couple of months until I saw what was happening in Baghdad and Iraq, and I have optimism for the first time. That doesn't mean we are going to find him alive, but I have optimism that we will find out at least about the fate of Captain Speicher."

Some hope has been given to Speicher's family. The initials "MSS" were found carved into the cell wall at Hakimiyah prison (search) in Baghdad. U.S investigators say they think that could stand for Michael Scott Speicher.

Nelson, who saw the cell, said he made a tracing of the initials to give to Speicher's family.

The investigation has been re-energized since the end of the war in Iraq a few months ago, and a $1 million reward is available for information in the case.

Fox News' Bret Baier and Caroline Shively contributed to this report.