Aides to U.S. President Joe Biden have discovered at least one more batch of classified documents in a separate location from the think tank office he used after serving as vice president, NBC News reported Wednesday, citing an unnamed source.

According to NBC News, Biden’s aides have been looking for additional classified material that may be elsewhere after a trove of classified documents was found at a Washington think tank in November.

The report says the classification, number and exact location of the additional documents are unknown.

The report also states that it is unclear when the additional documents were discovered and whether the search for other classified materials that Biden may have had from his time as vice president has been completed, Reuters writes.

The NBC News report comes two days after a White House lawyer said classified documents from Biden’s time as vice president were discovered in November by the president’s personal lawyers at the Penn Biden Center for Diplomacy and Global Engagement.

Several classified documents from President Joe Biden’s time as vice president were discovered last fall in a private office, CNN reports. The National Archives notified the Ministry of Justice for further investigation. Among the documents discovered are 10 classified materials, including US intelligence memos and reports, which dealt with topics such as Ukraine, Iran and Great Britain.

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