Bob Dudley, now CEO of BP, believed he was being poisoned during his stint working in Russia, and fled when he heard he was under imminent threat of arrest. This is according to a very good profile (paywall) in the latest issue of the New Yorker of Len Blavatnik, a billionaire oligarch who was a partner in a BP oil venture there.

If true (BP has declined to comment), the story explains an abiding mystery of BP’s mostly dark, so-far 17-year-long experience in Russia: that is, why did Dudley abruptly scamper out of Russia in 2008, and go into hiding?

The extraordinary episode occurred while Dudley was CEO of TNK-BP, a Moscow-based joint venture with four Russian oligarchs including Blavatnik. Extraordinary because even in the turbulent world of oil, you do not often get a senior executive going underground.

At the time, BP and its Russian partners were at war. The indications were that each side was seeking to push the other out of the company, or at least gain advantage in their working relationship. Always, the Kremlin seemed to be siding with the oligarchs. A Wikileaks cable from the period describes break-ins at Dudley’s Moscow apartment by intruders who left behind summonses to court hearings where the fleet-footed oligarchs were raising yet another complaint.

With that as a backdrop, according to the New Yorker account, Dudley began to feel ill, and poison was subsequently found in his blood. His condition improved once he stopped eating food provided by TNK-BP.

But on July 24, Dudley got word that police would detain him the next morning. That was when he left his apartment and flew out of the country.

Last year, both sides sold their holdings to Rosneft for a total of $55 billion in cash and shares—for its part, BP ended up with a 19.75% share of Rosneft, keeping it in the Russian orbit despite the nightmare.

Much of BP’s misery was its own fault—company executives who thought they knew how to manage an enterprise in Russia instead were continually outwitted, tripped-up and bamboozled. But the oligarchs themselves often seemed too gleeful, conduct that helped to deepen Russia’s and their own tarnished investment profile abroad.