The US government says the release of the Epstein files will take "a few more weeks" after a million additional documents were uncovered.
The Trump administration has blamed the document-review process for its failure to meet a legal deadline of December 19 to release all the files.
The Department of Justice (DOJ) said lawyers were "working around the clock" preparing files for release, but the mass discovery of more documents would hold things up further.
"We will release the documents as soon as possible," the DOJ said on X.
"Due to the mass volume of material, this process may take a few more weeks."
The intermittent rollout of the documents and the ways they have been redacted have inflamed the years-long controversy around the Epstein files.
Congress passed a law last month ordering the DOJ to publish all records relating to its investigations into sex criminals Jeffrey Epstein and Ghislaine Maxwell.
The legislation permitted only limited redactions to protect victims, ongoing investigations and national security.
Victims and Democrats have voiced suspicions about the redactions that have been made, saying it appears more details have been removed than legally allowed.
Hundreds of pages were completely blacked out in the first release of files.
But at least one victim, who had been trying to keep her identity private, found her name in the documents unredacted.
"It haunts me to my core," she told CNN.
CNN also reported the DOJ had asked more staff to join the redaction effort. An email to staff acknowledged the "timing could not be worse", but asked for more lawyers to volunteer to work over the "next several days".
The new documents were found by the US Attorney for the Southern District of New York, whose office investigated and charged Epstein and Maxwell for trafficking minors.
Epstein died while awaiting trial in 2019, and Maxwell was jailed for 20 years in 2021.
