Special counsel Jack Smith has charged a third defendant, Carlos De Oliveira, in the Trump Mar-a-Lago classified documents case, according to court files.

Former President Donald Trump and his aide, Walt Nauta, were previously charged last month. Both have pleaded not guilty to all charges.

De Oliveira was the maintenance worker who helped Nauta move boxes of classified documents around Mar-a-Lago after the Justice Department first subpoenaed Trump for classified documents last May.

CNN has previously reported that surveillance footage turned over to the Justice Department showed Nauta and De Oliveira, moving document boxes around the resort, including into a storage room just before Trump lawyer Evan Corcoran searched it for classified documents.

Justice Department officials came to Mar-a-Lago the day after Corcoran's search, and Corcoran handed over 38 classified documents he had found. Yet the FBI retrieved more than 100 more classified documents when it searched Mar-a-Lago in August, both in the storage room and Trump's office.

The Justice Department has subsequently said in court that it believes "government records were likely concealed and removed from the Storage Room."

De Oliveira spoke to investigators earlier this year and his phone had been seized.

This story has been updated with additional developments.