WASHINGTON — The Justice Department has launched an internal investigation into whether Attorney General Gonzales’s former White House liaison illegally took party affiliation into account in hiring career federal prosecutors, officials said yesterday.

The allegations against Monica Goodling represent a potential violation of federal law and signal that a joint probe begun in March by the department’s inspector general and Office of Professional Responsibility has expanded beyond the dismissal of eight U.S. attorneys last year.

The revelations about Ms. Goodling were among several developments yesterday in connection with the prosecutor firings, including a new subpoena seeking presidential adviser Karl Rove’s emails and new accusations from two of the dismissed U.S. attorneys.

In newly released statements, the two alleged that they were threatened by Deputy Attorney General Paul McNulty’s chief of staff immediately before Mr. Gonzales testified in the Senate in January.

Paul Charlton of Phoenix and John McKay of Seattle said Michael Elston called them on January 17 and offered an implicit agreement of silence by Mr. Gonzales in exchange for them continuing not to publicly discuss their removals. Mr. Gonzales testified before the Senate Judiciary Committee the next day and refused to provide details about the firings.

“My handwritten and dated notes of this call reflect that I believed Mr. Elston’s tone was sinister and that he was prepared to threaten me further if he concluded I did not intend to continue to remain silent about my dismissal,” Mr. McKay wrote in response to questions from the House Judiciary Committee.

Mr. Elston’s attorney, Robert Driscoll, said the calls were intended only to reassure the two prosecutors that Mr. Gonzales did not plan to reveal their dismissals, which were not public then.

“Mike didn’t intend to intimidate anybody,” Mr. Driscoll said.

Two other fired prosecutors complained pointedly about Mr. Elston, according to the statements released yesterday.

Carol Lam of San Diego wrote that Mr. Elston “erroneously accused me of ‘leaking’ my dismissal to the press, and criticized me for talking to other dismissed U.S. attorneys.”

Bud Cummins of Little Rock repeated his account of a February 20 phone conversation with Mr. Elston, two days after Mr. Cummins was quoted in a newspaper article. Mr. Cummins wrote that Mr. Elston “essentially said that if the controversy continued, then some of the USAs would have to be ‘thrown under the bus.'”

Mr. Elston has previously described Mr. Cummins’s reaction as the product of a misunderstanding.

The firing of eight U.S. attorneys last year — seven on them on one day — sparked a furor in Congress as Mr. Gonzales and other Justice officials offered shifting explanations for the move. Mr. McKay and another prosecutor, David Iglesias of New Mexico, also have alleged improper contacts from Republican lawmakers about ongoing criminal investigations, causing some Democrats to allege that some of the prosecutors were sacked for political reasons.

Lawmakers from both parties have called for Mr. Gonzales’s resignation, but President Bush has said that Mr. Gonzales will remain in his post.

A former deputy attorney general, James Comey, is scheduled to testify today before the House Judiciary panel.

Justice spokesman Dean Boyd said that as part of her job, Ms. Goodling reviewed applications for entry-level prosecutor positions in some offices headed by interim or acting U.S. attorneys. In those cases, Mr. Boyd said, Ms. Goodling “may have taken prohibited considerations into account” and “whether or not the allegation is true is currently the subject of the ongoing” investigation by the inspector general and the Office of Professional Responsibility.

Mr. Boyd noted that it is against federal law and internal Justice policies to consider political affiliation in hiring for non-political jobs.