Harassing emails sent by Paula Broadwell to her love rival, Jill Kelley, contained confidential information about David Petraeus’ movements, a law enforcement source has revealed.

After Jill Kelley contacted the FBI, agents launched a massive in-depth investigation into who was sending the emails because they shared this detailed information that was not publicly available.

The catty emails, which told Jill Kelley to “back off” from David Petraeus, were sent to Kelley from several fake email addresses. In order to find who had confidential information about David Petraeus’ whereabouts, the FBI obtained an administrative subpoena, and traced them back to Paula Broadwell.

In the course of the investigation, they also unearthed emails indicating the affair between Paula Broadwell and David Petraeus, leading to his resignation on Friday.

The new details of what uncovered David Petraeus’ months-long relationship with his biographer come as the FBI continue to search military documents Paula Broadwell admitted to stashing in her home.

Security officials have revealed she had “substantial” classified information on her computer which should have been stored more securely.

The computer was taken from Paula Broadwell’s Charlotte, North Carolina home on Monday night after she admitted to FBI investigators that she had taken classified military documents, a source told ABC.

FBI agents left Paula Broadwell’s Charlotte home on Monday evening with documents and computers

President Barack Obama said on Wednesday there was no indication so far that any classified documents had been found but said he will not prejudge the investigation results.

Officials continue to investigate exactly how Paula Broadwell acquired the files, but as an intelligence officer in the U.S. Military Reserve, she had security clearance to review the documents.

The government had demanded she return the documents and organized the visit to her home. Prosecutors are now deciding whether to charge her with a crime.

Paula Broadwell, who has kept a low profile since the scandal broke, was seen taking refuge at her brother’s home in the Petworth suburb of Washington D.C. on Tuesday night.

Preparing an evening meal with a glass of wine in her hand, the 40-year-old mother-of-two wore the strain of the last few days clearly on her face. There was no sign of her husband, Scott Broadwell.