CNN has not confirmed the WSJ report.
Monday’s search warrant execution pertained to both the handling of classified documents and the Presidential Records Act.
The concern arose after the former President returned some 15 boxes of materials to the National Archives in January.
Before FBI agents arrived at Trump’s private club earlier this week and searched his residence, people around the former President had been under the impression that the probe into how he handled classified information had stalled, according to two sources familiar with the thinking.
It remains unclear why those around the former President believed the investigation had stalled, but in June, his attorneys received a letter from investigators asking them to preserve the remaining documents in his possession “until further notice,” one source told CNN.
The Mar-a-Lago search, which focused on the area of the club where Trump’s offices and personal quarters are located, marked a major escalation of the classified documents investigation. Federal agents removed boxes of material from the Palm Beach property. The Secret Service had about an hour heads up before the FBI executed the warrant, a source familiar with the situation told CNN.