The FBI search of former President Donald Trump’s Mar-a-Lago residence on Monday was prompted by a tip to investigators about the possibility of additional classified documents at the Palm Beach club, according to a Wall Street Journal report. CNN previously reported that investigators from the FBI and the DOJ met with Trump attorneys at Mar-a-Lago in June, seeking more information about classified material that had been taken to Florida after Trump departed the White House. Following that meeting, where investigators looked around the room where the documents were being stored, the Wall Street Journal reports that “someone familiar with the stored papers told investigators there may be still more classified documents at the private club” beyond what Trump turned over to the National Archives earlier this year. 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. For months, investigators have been looking into how Trump handled material taken with him when he left the White House after the National Archives and Records Administration referred the case to the Justice Department earlier this year. The Monday search followed a belief from authorities that the former President or his team had not returned all the documents and other materials that were property of the government, according to a person familiar with the matter. There had been suspicion that Trump representatives were not being completely truthful with investigators, according to another person familiar with the matter. 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. The Wall Street Journal’s report comes amid increased pressure for the Justice Department to provide a public statement about the unprecedented move to search a former President’s home.