Peter Kadzik, the assistant attorney general of the U.S. Justice Department involved with the probe into Huma Abedin's emails, previously donated to Hillary Clinton and the daughter of Clinton campaign chairman John Podesta.

Kadzik sent a letter to a handful of congressional leaders on Monday stating that the department would work alongside the FBI and move as swiftly as possible in its probe of newly discovered emails from Abedin recovered from the laptop of her estranged husband, former Democratic congressman Anthony Weiner.

"The Department of Justice (the Department) appreciates the concerns raised in your letter. We assure you that the Department will continue to work closely with the FBI and together, dedicate all necessary resources and take appropriate steps as expeditiously as possible," Kadzik wrote.

Kadzik, who attended Georgetown University's law school with John Podesta in the 1970s and remains his close friend to this day, donated to Hillary Clinton's former leadership PAC and 2008 presidential campaign while working as an attorney at the D.C.-based law firm Dickstein Shapiro LLP.

Kadzik's first contribution to Clinton came on February 6, 2006, in the form of a $1,000 check to HillPAC, a leadership PAC started by Clinton while she was serving in the Senate.

Kadzik made two more contributions during Clinton's unsuccessful presidential run in 2008. The first donation was made on June 30, 2007 in the amount of $1,000. Kudzik donated an additional $1,300 on September 30.

Kadzik also donated $250 to Clinton's vice presidential candidate Tim Kaine during his Senate run in 2012.

Two years later, Kadzik donated $250 to the school board campaign of Megan Rouse, John Podesta's daughter. That donation was revealed by WikiLeaks in emails that were stolen from Podesta's Gmail account by hackers linked to the Russian government.

Podesta sent out a number of emails to close friends and acquaintances with details of a fundraiser for his daughter, who serves on a school board in California. The event was held at the Washington, D.C. home of Tony Podesta, John's brother and the head of the Podesta Group lobbying shop.

After the fundraiser, Rouse sent an email to Podesta with a spreadsheet of donations that included a $250 donation from Peter Kadzik contained in a $500 check from his wife, Amy Weiss.

Weiss, a public affairs specialist, served as White House deputy assistant and deputy press secretary to Bill Clinton.

Weiss contributed $2,300 to Hillary Clinton's presidential campaign in 2007, and donated twice more to Clinton this election cycle. Early in the Democratic primary campaign last year, Weiss donated $2,700 to Hillary for America. In September of this year, Weiss cut another $2,700 check to the Hillary Victory Fund, a joint fundraising committee that includes Clinton's campaign, the Democratic National Committee, and over 30 state-level Democratic parties.

A Justice Department spokesman said that Kadzik is not directly overseeing the investigation and that his job is to respond to inquiries from Congress.

UPDATE 4:01 P.M.: This post was updated to reflect comment from a Justice Department spokesman.