Former Connecticut Sen. Joseph Lieberman has withdrawn his name from the running for FBI director.
The confirmation comes after reports that President Donald Trump is expected to retain Marc Kasowitz as a private attorney on matters related to the Russia investigation.
Lieberman and Kasowitz are senior partners at the same firm and Lieberman's letter to President Donald Trump, which NBC Connecticut obtained, says he thinks it would be best to avoid the appearance of a conflict of interest.
News of Trump's plan to retain Kasowitz came after Deputy Attorney General Rod Rosenstein appointed former FBI Director Robert Mueller as a special counsel to oversee the investigation into alleged Russian interference in the U.S. presidential election between Trump and Hillary Clinton, and any possible collusion with members of the Trump campaign. Congressional committees in the House and Senate are also leading separate investigations.
"With your selection of Marc Kasowitz to represent you in the various investigations that have begun, I do believe it would be best to avoid any appearance of a conflict of interest, given my role as senior counsel in the law firm of which Marc is the senior partner,” Lieberman wrote.
“Once again, I am grateful for your consideration, and I wish you the very best in identifying the right person to lead this most important law enforcement agency in the future,” Lieberman’s letter says.
Lieberman was Trump's top pick to be the next FBI director to replace James Comey, who Trump fired earlier this month.
Joe Lieberman withdraws his name from consideration as FBI director pic.twitter.com/tTjGLjOOUV— NBC Politics (@NBCPolitics) May 25, 2017
The other three candidates include the current acting director, Andrew McCabe, former Oklahoma Gov. Frank Keating and Richard McFeeley, a former executive assistant director in the FBI.
Lieberman served 24 years as a Connecticut senator before retiring in 2013 after his fourth term.
He was the Democratic vice-presidential nominee, running with Al Gore in 2000. The pair lost the election to George W. Bush and Dick Cheney in a result that needed to be decided by the Supreme Court.
Lieberman also served as Connecticut's attorney general and spent 10 years as a state senator.