NEW YORK (Reuters) - A former U.S. Justice Department official has become the latest lawyer to join special counsel Robert Mueller’s team investigating Russia’s interference in the 2016 presidential election, a spokesman for the team confirmed.

Special Counsel Robert Mueller departs after briefing the U.S. House Intelligence Committee on his investigation of potential collusion between Russia and the Trump campaign on Capitol Hill in Washington, U.S., June 20, 2017. REUTERS/Aaron P. Bernstein

Greg Andres started on Tuesday, becoming the 16th lawyer on the team, said Josh Stueve, a spokesman for the special counsel.

Most recently a white-collar criminal defense lawyer with New York law firm Davis Polk & Wardwell, Andres, 50, served at the Justice Department from 2010 to 2012. He was deputy assistant attorney general in the criminal division, where he oversaw the fraud unit and managed the program that targeted illegal foreign bribery.

Mueller, who was appointed special counsel in May, is looking into possible collusion between the Trump campaign and Russia during the election, among other matters. Congressional committees are also investigating the matter.

That Mueller continues to expand his team means the probe is not going to end anytime soon, said Robert Ray, who succeeded Kenneth Starr as independent counsel for the Whitewater investigation during the Clinton administration.

“It’s an indication that the investigation is going to extend well into 2018,” said Ray. “Whether it extends beyond 2018 is an open question.”

The special counsel last month asked the White House to preserve all of its communications about a June 2016 meeting that included the president’s eldest son, Donald Trump Jr., his son-in-law and adviser Jared Kushner, and Russian lawyer Natalia Veselnitskaya.

Russian officials have denied meddling in the U.S. election, and Trump denies any collusion by his campaign.

Among the cases Andres oversaw at the Justice Department was the prosecution of Texas financier Robert Allen Stanford, who was convicted in 2012 for operating an $8 billion Ponzi scheme.

Before that, Andres was a federal prosecutor in Brooklyn for over a decade, eventually serving as chief of the criminal division in the U.S. attorney’s office there. He prosecuted several members of the Bonanno organized crime family, one of whom was accused of plotting to have Andres killed.

A graduate of Notre Dame and University of Chicago Law School, Andres was a Peace Corps volunteer in Benin from 1989 to 1992.

He is married to Ronnie Abrams, a U.S. district judge in Manhattan nominated to the bench in 2011 by Democratic President Barack Obama.

Others on the special counsel team include Andrew Weissmann, chief of the Justice Department’s fraud section; Andrew Goldstein, former head of the public corruption unit at the U.S. Attorney’s Office in Manhattan; and James Quarles, who was an assistant special prosecutor in the Watergate investigation that helped bring down President Richard Nixon.

(Story refiles to correct typographical error in paragraph 11 to Andres instead of Andrews.)