WASHINGTON -- Federal prosecutors are reviewing evidence gathered by investigators into whether scientists falsified quality assurance documents at Yucca Mountain, officials confirmed Friday.

Inspectors general for the Interior and Energy departments sent a report to U.S. Attorney Daniel Bogden in Las Vegas in the past month, said Roy Kimes, a spokesman for Interior Department Inspector General Earl Devaney.

"The investigative work has been done, and the report has been forwarded to the Department of Justice," Kimes said. "It is not considered finalized until we get an indication from DOJ that they are going to prosecute or not going to prosecute."

Neither Kimes nor Denise Smith, a spokeswoman for Energy Department Inspector General Gregory Friedman, would discuss details.

Smith said "it is possible" that evidence of wrongdoing was discovered, but communications between investigators and prosecutors do not necessarily signal the probe is near an end.

"As evidence is uncovered, there are dealings with the U.S. attorney's office, and oftentimes the U.S. attorney may have us do additional work or not depending on what is found," Smith said.

Inspectors were asked to determine possible criminal activity by federal employees after the disclosure in March 2005 of provocative e-mails.

In the messages, which were written between 1998 and 2000, several workers discussed possible alterations of quality assurance documents that backed up their water infiltration models at the nuclear waste site.

Natalie Collins, an aide to Bogden, said she would not confirm or deny the federal attorney's involvement in the matter.

A person familiar with the process said, "I wouldn't think they would send something over (to Bogden) that they didn't think ought to be considered for prosecution."

On Thursday, Rep. Jon Porter, R-Nev., told reporters that a Justice Department evaluation "was forthcoming."

"They want to find out if it was done maliciously or done in error," Porter said of the allegations of document mishandling. "They want to find out if there was any criminal activity."

Porter heads a House subcommittee that has been conducting a separate probe of quality assurance at Yucca Mountain and issues related to the e-mails.

The Yucca project was rocked and investigations were triggered when the e-mails were disclosed by Energy Secretary Samuel Bodman and by Charles Groat, then-director of the U.S. Geological Survey.

The messages circulated among a small number of employees. The primary authors later were identified as USGS hydrologists Joseph Hevesi, Allen Flint and Lorraine Flint.

Hevesi appeared before Porter's subcommittee in June and offered explanations for some of the messages. He testified under oath that he did not alter documents or data. The Flints, who are married, were questioned by subcommittee investigators but have not commented publicly.

The Energy Department recently completed an audit of the work performed by the USGS scientists. A report issued Feb. 17 concluded the science was valid but the research would be redone by Sandia National Laboratories to meet quality assurance standards.

The hydrologists remain employed at the USGS, spokeswoman A.B. Wade said. Agency officials have said any possible disciplinary action was being postponed until completion of the inspectors general probe.

Review-Journal writer Keith Rogers contributed to this report.