A Russian investigative journalist who wrote about the deaths of Russian mercenaries in Syria has died after falling from his fifth-floor apartment balcony.
News website Novy Den (New Day) said its reporter Maxim Borodin died at a hospital on Sunday (local time).
Borodin was reportedly found on the ground of his apartment in Yekaterinburg by neighbours on Thursday, but the cause of the fall was unclear.
Russian news reports cited police as saying the apartment was locked from the inside.
In March, Borodin wrote about bodies believed to be those of Russian mercenaries being delivered to a regional village.
Thousands of mercenaries have reportedly been deployed to Syria by the shadowy contracting company known as Wagner, believed to be bankrolled by Yevgeny Prigozhin, a St Petersburg entrepreneur dubbed "Putin's chef" by Russian media because of his restaurants and catering businesses that once hosted the Kremlin leader's dinners with foreign dignitaries.
Mr Prigozhin was indicted by the US in February on charges that he funded the "troll factory" alleged to have tried to influence the 2016 presidential election.
Reporters Without Borders (RSF) has called for a full and impartial investigation into Borodin's death.
"We extend our heartfelt condolences to Maxim Borodin's family and colleagues, and we demand a full and impartial investigation into his death," Johann Bihr, the head of RSF's Eastern Europe and Central Asia desk, said in a statement.
"In view of the highly sensitive nature of his investigative reporting, all hypotheses must be given serious consideration, including the possibility that he was murdered in connection with his reporting."