Former President Donald J. Trump hired people to search three of his properties after being directed by a federal judge to look harder for any classified material still in his possession, and they did not find anything, according to two people familiar with the events.

The searches, which were completed around Thanksgiving, were conducted at Mr. Trump’s golf club in Bedminster, N.J.; at Trump Tower in New York; and in a storage area at Mar-a-Lago, his private club and residence in Florida, according to the people familiar with the events.

The New York Times reported in October that Justice Department officials had told the former president’s lawyers that they believed he might have more classified materials that were not returned in response to a subpoena issued in May. The F.B.I. searched Mar-a-Lago in August for additional classified documents and other presidential records.

After the warning from the Justice Department, a debate ensued among Mr. Trump’s lawyers about whether to bring in an independent firm to conduct a search.