The Trump administration's State Department is intensifying its investigation into the email records of dozens of former department officials and aides to former Secretary of State Hillary Clinton.

As many as 130 officials have been recently contacted by investigators from the State Department, current and former officials told the Washington Post. According to the outlet, those targeted were contacted by the department about emails they sent years ago that have been retroactively classified and could now count as possible security violations. Investigators began communicating with former officials around 18 months ago, but they appeared to suspend the effort before ramping it back up in August.

Although some who are under scrutiny view the recent activity as the Trump administration's decision to wield power against political adversaries, senior State Department officials said they are simply following standard protocol in an investigation that initially started during the Obama administration.

“This has nothing to do with who is in the White House,” one official said. “This is about the time it took to go through millions of emails, which is about 3 and a half years.”

“The process is set up in a manner to completely avoid any appearance of political bias,” another official added.

Former Obama administration officials, however, told the Post that the investigation is an "aggressive crackdown" by an administration that has had its own problems with handling classified information.

The list of State Department officials being questioned includes assistant secretaries of state responsible for U.S. policy in the Middle East, Europe, and Central Asia, as well as several ambassadors. It also includes many current and former bureaucrats who passed along important messages to Clinton from outside officials. Many of those targeted have been found "not culpable," while some were sent follow-up letters saying that investigators “determined that the [security] incident is valid” but that they did not “bear any individual culpability."

The State Department review began after the FBI investigated Clinton's use of an unauthorized server, hosted in the basement of her home in Chappaqua, New York, during her time as secretary of state from 2009 to 2013. Former FBI Director James Comey publicly recommended in 2016 that no charges be brought against Clinton or anyone else involved with her private email network, but he admonished Clinton and her team for being "extremely careless" in handling classified information.

This was during the 2016 election when Clinton was the Democratic presidential nominee, and she has often cited the FBI's handling of the emails investigation as one of the reasons why she believes she lost the contest to President Trump.

One of the main controversies stemming from Clinton's emails was how Paul Combetta, the tech aide who administered the server, deleted 33,000 emails despite a congressional order to preserve them. The FBI says it was only able to recover about 5,000 of the emails scrubbed by Combetta, and they were released in tranches up until earlier this year as part of a lawsuit brought by Judicial Watch. Clinton has said she "never received nor sent any material that was marked classified," but the FBI found 110 emails did contain classified information.

As recently as last week, Trump called the deletion of the emails "one of the great crimes committed" by Clinton. Also last week, the Democratic-led House initiated a formal impeachment inquiry, spurred by an intelligence community whistleblower complaint that raised concerns about a possible effort to pressure Ukraine to investigate Joe Biden, who is running for president in 2020, and an alleged effort to conceal details of Trump's July 25 phone call with Ukrainian President Volodymyr Zelensky and communications with other leaders.

Earlier this summer, the State Department informed Congress that its review of the mishandling of classified information found 23 "violations" and seven "infractions" by 15 individuals. A "broad range" of disciplinary or administrative actions that could be taken include "counseling, reprimand, suspension, and/or separation," according to a letter in June from Mary Elizabeth Taylor, the assistant secretary of state for legislative affairs.

The individuals were not identified, nor was it revealed if they were still employed at the State Department, per agency policy, and Taylor said the number of people found culpable could increase.

Taylor sent a letter to Sen. Chuck Grassley, a Republican from Iowa, who is leading the congressional oversight of the security review. Grassley has repeatedly asked for updates on the State Department's review since 2017. In her letter, Taylor acknowledged that the large number of emails under scrutiny required "a significant dedication of time and resources." Taylor said the agency was "making every effort to complete its review and adjudication" by Sept. 1, 2019.

Later in June, Republicans called on the Democrat-led House Oversight Committee to hold a hearing focusing on the State Department's review, but so far have been ignored.

Clinton's security clearance was withdrawn in the fall of 2018 at her request, along with those belonging to Clinton's former chief of staff Cheryl Mills and others.