An aide to former US President Donald Trump pleaded not guilty on Thursday to additional federal charges that accused him of misleading investigators who were trying to recover classified documents that Trump took with him when he left office, Reuters reported.

Trump's valet Walt Nauta pleaded not guilty to charges of obstruction of justice and false statements in an appearance before US Magistrate Judge Shaniek Mills Maynard in Florida.

Another aide, Carlos De Oliveira, a property manager at Trump's Mar-a-Lago resort in Florida, appeared alongside Nauta but did not enter a plea as lawyers said he does not yet have a local lawyer licensed to practice in the state.

Nauta and De Oliveira were both charged with conspiring with Trump to thwart a year-long investigation into his retention of the documents.

Trump has pleaded not guilty to 40 counts of unauthorized retention of national defense information, obstruction of justice and false statements. He appeared at an arraignment in June.

Prosecutors have accused Trump of taking top-secret documents with him when he left the White House in 2021 and storing them haphazardly at Mar-a-Lago.

Nauta moved boxes of documents at Mar-a-Lago to hide them from Trump's lawyer and federal investigators, according to prosecutors. He and Oliveria are accused of trying to delete security camera footage and lying to the FBI.

Nauta had previously pleaded not guilty to some charges in the documents case, but returned to court to face additional counts filed in a superseding indictment in July.

De Oliveira was added as a third defendant in the second indictment. Lawyer John Irving said he should have local counsel lined up by Friday and will be able to enter a plea on Aug. 15. De Oliveira is not expected to appear in court for that hearing, according to Reuters.