WASHINGTON - The US Justice Department is said to have retrieved more than 300 documents with classified markings from Donald Trump since January.

The initial batch of documents retrieved by the National Archives from the former president in January included more than 150 marked as classified, a number that ignited intense concern at the Justice Department and helped trigger the criminal investigation that led F.B.I. agents to swoop into Donald Trump’s Mar-a-Lago residence in Florida this month.

In total, the government has recovered more than 300 documents with classified markings from Mr. Trump since he left office, the people said: that first batch of documents returned in January, another set provided by Mr. Trump’s aides to the Justice Department in June and the material seized by the F.B.I. in the search this month.