Proyekt (The Project), one of Russia’s last independent media outlets specializing in in-depth investigations, said police were raiding the homes of its editor-in-chief Roman Badanin and journalist Maria Zholobova.
Another journalist, deputy editor Mikhail Rubin, was detained while police searched his parents’ apartment, the news outlet said on social media.
The searches came before the planned release of an investigation into the alleged wealth of Interior Minister Vladimir Kolokoltsev, his son and other relatives, Proyekt said.
“But we will post it anyway,” the news outlet said on the Telegram messaging app.
Critics of the Kremlin say that during his two decades in power, President Vladimir Putin has silenced most dissidents and gagged the media.
The few independent and opposition media outlets still operating in Russia are under enormous pressure, Kremlin opponents say.
In April, the authorities designated Meduza, a popular Russian-language news website based in Latvia, as a “foreign agent”, forcing it to launch a crowdfunding campaign to survive the loss of advertising revenue.
The following month, another independent online media outlet, VTimes, received the same day and closed in June.
Groups or individuals identified as “foreign agents” in Russia must disclose their funding sources and tag posts with the appropriate label or face fines.
The designation is seen as a deterrent to advertisers, and staff at publications with the label say the stigma makes the job difficult, including the sources they cite.
Russia will hold parliamentary elections in September and, before the elections, the authorities declared the organizations of the jailed Kremlin critic Alexei Navalny extremists and banned the participation of his allies.