The allegations, if true, would throw into doubt hundreds of criminal cases dating back at least a decade.
The examiner on June 2 admitted to making a false entry on a control sample used during one DNA examination, and the laboratory is now reviewing 479 or more cases the accused examiner has worked on since he began in 1995, according to an announcement Friday by the Army Criminal Investigation Command, or CID.
The examiner was suspended from duty in May after the allegations surfaced. His name was not released.
The lab at Fort Gillem is the only Army facility that performs forensic examinations in support of military criminal cases. It provides services to all military investigative agencies and is the only accredited full-service crime lab in the federal government outside the FBI.
This was not the first indication of potential problems at Fort Gillem. The examiner now under investigation was temporarily suspended from DNA case work in January 2004 when contamination was detected in his testing process, officials said. After "remedial action and retraining" he was returned to work in September 2004.
No other details of the earlier suspension were released Friday.
"We are taking every step necessary to ensure we have an independent, impartial review of the issues at hand," said Chris Grey, a CID spokesman. "At this time the incident appears to be isolated to one individual examiner, but we want to take very step necessary to make certain that is the case."
The CID investigation is being led by the command's Standards of Conduct Office, and the Pentagon's inspector general has been asked to conduct an independent review of the CID probe once it has been completed.