According to Newsweek, the death of Ivan Sechin, a 35-year-old employee of Rosneft, the Russian oil company owned by the state, was shrouded in mystery. He was the son of Igor Sechin, a close associate of Russia’s President Vladimir Putin. His demise was not made public until Leonid Nevzlin, a former oil tycoon and a vocal opponent of Putin, revealed it.

Nevzlin said on social media that he found mention of Sechin’s death in Russia’s national register of inheritance cases.

According to Nevzlin, the entry said that Ivan Sechin, born in 1989, lived in a building that was previously described as “a house for President Putin’s associates.”

In his Facebook post, Nevzlin said death of Ivan Sechin was a “strange coincidence.”

“Today, when we recalled with my friends and partners why the Kremlin war against Yukos began…it was today that I learned that Igor Sechin had just lost his son. The very same man who fabricated every blatant and bloody case against us. And still,” he said in his post.

“Probably hard to believe but my heart goes out to a father who lost his child. How I sympathize with Alexei Navalny’s mother. How I sympathized in recent years to Bory Nemtsov’s mother, who left us this month,” Nevzlin added. “My condolences to Sechin’s family, who are forced to hide their grief.”

Many prominent Russians have inexplicably died since Russia invaded Ukraine in February 2022.

Pavel Antov, a wealthy tycoon and a member of Putin’s United Russia party had once criticised Russian invasion of Ukraine. In December 2022, he was found dead after falling from a window in India.

Most recently Russian opposition figure Alexei Navalny died while serving prison sentence in a penal colony in Russia.