A company run by Russian businessman Yevgeny Prigozhin, purportedly close to President Vladimir Putin, on Wednesday said he was pursuing a libel settlement against opposition leader Alexei Navalny.

Prigozhin’s Concord catering company said in a statement it was seeking 840,000 euros ($900,000) in damages as it looks to “defend its honor, dignity and commercial reputation.

“The total claims amount to 77 million rubles (more than 840,000 euros),” Concord stated in response to a request for information from the Interfax news agency.

Prigozhin, 59, is demanding damages following an August legal settlement against Navalny’s Anti-Corruption Foundation after it accused his catering firm of supplying sub-standard food to schools and not meeting sanitary standards.

Concord also provides catering services to the Kremlin, earning Prigozhin the nickname of “Putin’s Chef.”

A Moscow court in October ordered Navalny, currently in Germany where he was taken for treatment following an alleged poisoning in August while on an investigation in Siberia, to pay damages.

A thorn in the flesh of Putin and his government, Navalny has promised to return to his homeland.

Tuesday saw Russian authorities open a criminal probe into Navalny, alleging he used more than 356 million rubles ($4.8 million) of donations to his organizations for personal purposes including holidays abroad.

The Investigative Committee, which probes major crimes, said in a statement that the money was part of more than 588 million rubles Navalny had raised “exclusively” for his nonprofit organizations, including the Anti-Corruption Fund.

The charge carries a penalty of up to 10 years in prison.