"No, we do not know anything about it. The Mueller probe is surrounded by mayhem. Let's say, we have not seen any materials that could be called serious in any open sources yet," Peskov told reporters, asked to comment on media reports on the leakage of the case's materials.
The statement comes after Mueller said in a court filing on 30 January that materials that were in possession of Russian company Concord Management, which is also being probed as part of his investigation, were "altered and disseminated as part of a disinformation campaign aimed (apparently) at discrediting ongoing investigations into Russian interference in the US political system".
READ MORE: US Evidence in Concord Management Case 'Altered, Disseminated' — Mueller
On February 16, the US Justice Department said that the United States had indicted 13 Russian nationals and three entities, including Concord Management, for allegedly trying to interfere in the 2016 US presidential election.
Moscow has denied all claims of meddling. The firm's lawyers have made several attempts to appeal the charges, but the defendant's motions were dismissed.