The total number of classified documents found in the private offices of US President Joe Biden amounts to 20, CBS News reported, citing a US law enforecement official familiar with the investigation. 
 
Around ten classified documents were discovered at the Penn Biden Center, a Washington-based think tank, and included top-secret information, the highest of the three levels of document classification in the United States, according to the broadcaster, citing an official.
 
Other classified documents were found at Biden's residence in Wilmington, Delaware, making the total number of known documents roughly 20, CBS News said. 
 
US Attorney General Merrick Garland stated on Thursday that he has concluded that it is in the public interest to appoint a special counsel to investigate the alleged mishandling of classified government documents during Biden's tenure as US Vice President.

Congressman Paul Gosar told Sputnik on Thursday that Republican lawmakers will investigate the matter as a serious felony, which is punishable with a prison sentence of up to 10 years.

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Earlier, Biden said on January 11 that he was "surprised" to learn that classified documents were taken to his personal office after he left the vice presidency and that he has no idea what is in the records. Meanwhile, Democratic and Republican leaders on Capitol Hill demanded more information about the discovery that prompted a Justice Department investigation.

“I was briefed about this discovery and surprised to learn that there are any government records that were taken there to that office,” Biden said during a news conference in Mexico City.

“But I don’t know what’s in the documents. My lawyers have not suggested I ask what documents they were. I’ve turned over the boxes — they’ve turned over the boxes to the Archives. And we’re cooperating fully — cooperating fully with the review, which I hope will be finished soon, and there will be more detail at that time,” he added.

A day after, Biden's aides discovered at least one additional batch of classified documents in another location that was used by him after serving as vice president, US media outlets reported on Wednesday, citing unnamed sources.

NBC News and CNN said Biden aides have been searching for additional classified documents that might be in other locations since a first batch of classified documents was found in November at the Penn Biden Center for Diplomacy and Global Engagement think tank in Washington.

According to NBC News, the classification level, number, and exact location of the additional documents were not immediately clear, adding that it was also not clear when the additional documents were discovered.

Read next: DOJ reviewing potentially classified documents at Biden center: WH