The Justice Department said yesterday it has opened a criminal investigation of a civilian contractor in connection with the abuses at Abu Ghraib prison in Iraq.

Neither the Justice Department nor the Defense Department would identify the contractor. "We remain committed to taking all appropriate action within our jurisdiction regarding allegations of mistreatment of Iraqi prisoners," Mark Corallo, Justice Department director of public affairs, said in a statement. A Pentagon spokesman declined to comment.

Meanwhile, Titan Corp., which provided translators at the prison, confirmed yesterday that it had terminated an employee, Adel L. Nakhla, who was cited in an Army report on the abuses there.

Nakhla was one of three civilian contract employees who were criticized in the report. He was listed as both a suspect and a witness, although there are no allegations against him spelled out in the portion of the report that has been publicly released. Several thousand pages of the report remain classified.

Nakhla's wife, Nadine, answered the door of their two-story townhouse in Montgomery Village yesterday and referred questions to a lawyer, Francis Hoang. He did not return messages left at his office.

A lawyer for Steven A. Stefanowicz, another of the civilian contractors, said he was not aware of an investigation of his client.

The Army report on the prison abuses said Stefanowicz, an interrogator employed by Arlington-based CACI International Inc., "allowed and/or instructed MPs, who are not trained in interrogation techniques, to facilitate interrogations by 'setting conditions' which were neither authorized and in accordance with applicable regulations/policy. He clearly knew his instructions equated to physical abuse."

Stefanowicz's attorney, Henry E. Hockeimer Jr., said his client did nothing wrong.

The third civilian identified in the report, John Israel, is accused in the Army report of lying to investigators about seeing interrogations that violated the rules. Israel could not be reached to comment. He worked for a Titan subcontractor, SOS Interpreting Ltd.

"He was an employee of SOS -- I am not sure if he is at this point," said Bruce Crowell, chief financial officer of SOS Interpreting.

Titan spokesman Ralph "Wil" Williams confirmed that Nakhla had been terminated, but declined to say why, citing a company policy of personnel confidentiality.

Nakhla gave sworn statements to Army investigators who were probing abuses at Abu Ghraib and was questioned about several detainees who had been accused of rape, according to the Army report by Maj. Gen. Antonio M. Taguba.

In a statement to investigators obtained by The Washington Post, Nakhla said he served as a translator when a juvenile detainee alleged that he had been sexually assaulted by two older cellmates.

Nakhla said MPs who were investigating ordered the detainees who had been accused to "do strange exercises by sliding on their stomach . . . then they handcuffed their hands together and their legs with shackles and started to stack them on top of each other."

Nakhla said in the statement he tried to intervene on behalf of the prisoners, telling the MPs "that this is not an acceptable behavior in this society and that other inmates are not happy with what is happening which finally convinced the MP's to stop doing this."

Asked why he did not report the abuses to higher authorities, Nakhla told investigators: "I have seen soldiers get in trouble for reporting abuse, and I was scared. I didn't want to lose my job."

Staff writers Ellen McCarthy and Brigid Schulte contributed to this report.

Army Maj. Gen. Antonio M. Taguba reported "sadistic, blatant and wanton criminal abuses" at the U.S.-run Abu Ghraib prison near Baghdad.