The release of the records is the latest of several instances in which the Clinton White House has declared a document search to be exhaustive, only to later stumble on important material. For example, White House officials initially said that Vincent W. Foster Jr., the deputy White House counsel, left no indication of why he committed suicide on July 20, 1993. But later, an aide found the remnants of a note describing Mr. Foster's disenchantment with Washington.

Mr. Kendall said the Rose billing records were discovered in the White House on Thursday night by Carolyn Huber, a White House aide and former office manager of the Rose firm. He also said Mrs. Clinton was not aware until today that the records had been in the White House.

Henry F. Schuelke, a lawyer for Mrs. Huber, said tonight that she found the records in a storage area in the third-floor private residence at the White House where unsolicited gifts to the President and First Lady are stored before being sorted and catalogued.

Mr. Schuelke said Mrs. Huber did not know who placed the records in the storage area or how long the material might have been there. "It could have been there for months," he said. "She has no idea how long it was there."

He said she discovered the material after she had brought the documents, along with some of the unsolicited gifts, to her own office in the White House East Wing.

When she examined the documents, Mr. Shuelke said, she realized the materials might be relevant to the various inquiries. Mr. Schuelke said she then called him and alerted Mr. Kendall.

Mr. Kendall declined to say why Mrs. Huber had been going through the files or how the Rose documents could have come into the possession of the White House in the first place. He also declined to answer questions about why they were not discovered sooner.