Special counsel Robert Mueller has hired Greg Andres, a former Justice Department official, as the newest member of his team investigating Russia's interference in the 2016 election, according to a report Tuesday night.

Andres is the 16th lawyer to join Mueller's team, according to Reuters.

He served in the Justice Department from 2010 to 2012, working as deputy assistant attorney general in the criminal division, where he oversaw the fraud unit and led the program that focused on illegal foreign bribery.

Andres was most recently a white-collar criminal defense attorney with the New York law firm Davis, Polk, & Wardwell.

He is married to Ronnie Abrams, a U.S. district judge in Manhattan appointed by former President Barack Obama.

Mueller's probe covers whether the Trump campaign conspired with Russia. He is also reportedly exploring whether President Trump obstructed justice in trying to limit the investigation.

Last month, Bloomberg reported Mueller's investigation expanded to include Trump and his associates' business transactions.

Mueller has assembled a high-powered team to help with the probe, including: 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.

Trump and his supporters have criticized Mueller's team because some of the attorneys have donated to Democratic politicians, including Hillary Clinton.