The new investigation follows a spate of suspicious deaths involving officials and business people from Vladimir Putin‘s Russia.
Reports have suggested Nikolai Krobrinets died of a heart attack after checking into a hotel in Turkish city Istanbul‘s Taksim district.
He was there to attend a summit of different nations’ ambassadors.
Mr Kobrinets was discovered dead in his hotel bed after colleagues raised concerns when he didn’t make a morning meeting, reports say.
Cops are now investigating, while his body has been taken to the the morgue of the Forensic Medicine Institute in Bahçelievler Yenibosna.
A post-mortem is due to be held, while police are also checking his hotel room for fingerprints and scrutinising CCTV footage.
Initial reports suggested he died after suffering a heart attack, but inquiries are continuing.
Security experts have accused Russian president Putin of running a “mafia” state with murder as a tool to defeat foes and keep allies in line.
Wagner Group warlord leader Yevgeny Prigozhin became in August among the latest added to a body count of at least 40 high-profile deaths.
Dozens of prominent figures have died since Putin launched his invasion of Ukraine in February last year – many in mysterious and sudden circumstances, including “suicides” and falling from windows.
On August 23 Prigozhin’s private plane was blasted 28,000ft out of the sky, just days after he attempted a coup against Putin.
The Sun Online has calculated at least 40 suspicious deaths since January last year.
Sergey Grishin, the so-called “Scarface” oligarch who sold Meghan, the Duchess of Sussex, and Prince Harry their California mansion, died from sepsis in March after criticising the Russian tyrant Putin.
Russian scientist Andrey Botikov, who came up with the “Sputnik V” vaccine, was strangled with a belt in his flat that same month.