The U.S. Attorney's Office in Washington, DC on Thursday moved to dismiss the case -- and a retrial -- against Ingmar Guandique, the illegal immigrant previously convicted of murdering intern Chandra Levy in May 2001, citing "unforeseen developments."

The U.S. Attorney's Office dropped charges against Ingmar Guandique on Thursday. (AP)

Guandique, an illegal immigrant from El Salvador, is set to be released to U.S. Immigration and Customs Enforcement for removal proceedings.

The 2010 conviction of Guandique -- and the 60-year prison sentenced imposed on him at the time -- was vacated and a new trial was ordered in 2015 based on what Guandique's defense team said was new evidence.

"Today, in the interests of justice and based on recent unforeseen developments that were investigated over the past week, the Office moved to dismiss the case charging Ingmar Guandique with the May 2001 murder of Chandra Levy," the U.S. Attorney's Office said in a statement. "The Office has concluded that it can no longer prove the murder case against Mr. Guandique beyond a reasonable doubt."

Levy's 2001 disappearance created a national sensation after the Modesto, California, native, and intern with the Federal Bureau of Prisons, was romantically linked with then-Congressman Gary Condit.

July 11, 2001: Then-Rep. Gary Condit, D-Calif., leaves his Washington apartment.

The remains of the 24-year-old were found in Washington's Rock Creek Park in 2002. Prosecutors argued her death fit a pattern of attacks Guandique committed on female joggers.

Condit was a suspect in Levy's murder for a period of time, and Guandique's defense team reportedly planned to introduce evidence at the retrial implicating him in Levy's death.

Condit, a Democrat, left Congress in 2003 after losing his party's primary to an ex-aide.

The Associated Press contributed to this report.