MOSCOW (AP) — Three key editors at top Russian media holding firm RBC said Friday they have resigned amid a flurry of probes and police raids around the company.

RBC's web-site was ranked the most-visited news website in Russia last year, just a few years after the company was bought by billionaire Mikhail Prokhorov, better known as the owner of Brooklyn Nets, who hired arguably Russia's best journalists and editors.

RBC said in a statement Friday the resignations of Elizaveta Osetinskaya, Maxim Solyus and Roman Badanin were effective immediately. It quoted RBC director general Nikolay Molibog as saying the management and the editors "have failed to agree on a number of crucial issues."

RBC last year broke the news about a woman reported to be President Vladimir Putin's daughter and the business of a man reported to be her husband. Putin, who has kept his family life secret throughout his presidency, has neither confirmed nor denied his relation to the woman.

Days after RBC's profile of billionaire cellist Sergei Roldugin — a longtime friend of Putin's who was linked to offshore accounts revealed by the Panama Papers — FSB intelligence officers came to search Prokhorov's offices. A few weeks later, the country's top investigators opened a fraud probe against RBC.

Badanin, editor-in-chief of RBC's news service, told The Associated Press that the pressure on RBC precipitated the resignations. The editors and management's "views on the editorial policy have diverged as the company found itself under pressure," Badanin said.

Osetinskaya, who starts a journalism fellowship at Stanford University in September, on Friday thanked her team on Facebook but said she would not comment further.

Three more RBC editors said they resigned later Friday after the RBC statement.

Despite the decade-long crackdown on independent media in Russia, certain media outlets have retained some editorial independence and have reported stories critical of the Kremlin. Most of them, however, remained small and their audience was negligible, compared to RBC's wide reach.