The State Department has reportedly ramped up an investigation into Hillary Clinton’s use of a private email server while secretary of state, rekindling one of the themes of the 2016 presidential election that had crowds at Trump rallies chanting “lock her up.”

As many as 130 former Clinton aides have been contacted in recent week and alerted that emails sent years ago have now been deemed classified and may be considered security violations, the Washington Post reported Saturday.

In almost all of the cases, the communications were sent to Clinton’s unsecured server.

The probe first began after President Donald Trump’s election but then languished until the effort picked up new life in August.

The State Department said it is standard procedure to continue and investigation that began in the waning days of the Obama administration.

“This has nothing to do with who is in the White House,” a senior State Department official was quoted as having told the Washington Post. “This is about the time it took to go through millions of emails, which is about 3½ years.”

Adrienne Elrod, ​a spokeswoman for Clinton’s presidential run, said she doubted that explanation. “This headline would be more accurate if it began with the words, ‘In a politically biased effort to deflect …,’” she said in a tweet.​​

Clinton characterized the FBI’s investigations into her server as among the main reasons she lost to Trump.

Then–FBI Director James Comey announced in July 2016 ​that the department was not recommending criminal charges against her, even though she had been, in his words, “extremely careless” in using the private server.

Later, just weeks before November’s election, Comey notified Congress that the FBI was reopening the probe before shutting it down again on Nov. 6 — two days before the election.

This report originally appeared on NYPost.com.