Ukrainian site http://censor.net , citing security sources, provides a version of events surrounding the arrest - and then release - of 32 RU mercenaries who traveled to Belarus end of July. The story appears more plausible than either the Belarus or Russian claims so far.

The arrival of the "Wagnerites" to Belarus was indeed a covert operation by Ukraine's SBU and GUR (military intel). It had been planned over a year. The goal was to detain approximately 28 wanted unlawful combatants, 9 of whom Ukrainian citizens, and 2 linked to #MH17.

To this end, Ukraine's secret services indeed brought back to life a disused St. Petersburg private military company (MAR), and engineered a sophisticated game plan to recruit over a hundred ex mercenaries - while their targets were specifically the 28 wanted persons.

During the "job interviews" via video chat, they had the 28 talk about their "professional achievements", thus admitting both to their unlawful warfare in Donbass, Syria etc, and to specific crimes: being complicity to the shoot down of MH17 and a Ukranian transport plane etc

Apparently, Ukraine's services had arranged for the onward flight taking off from Minsk to Istanbul to make an emergency landing in Kyiv. There the 28 would have been arrested and the plane would have continued onward to Istanbul. However, there was a leak...

http://Censor.net  believes the leak to Russia came from Ukraine's presidential administration *after* the mercenaries had crossed into Minsk. They were prevented from boarding the plane to Istanbul, and were arrested theatrically in a show that seemed to serve Luka's goals.

Notably, a few days after the arrest by Belarus (and thus the failure of the presumptive SBU/GUR operation), Zelensky fired the GUR chief. According to the website, he (GUR's boss Burba) had just insisted on treason investigation against the leaker.

This version of events in more detail here: (in Russian) https://m.facebook.com/story.php?story_fbid=4455945144445747&id=100000909172681

While this version is thinly sourced (for now), it is the only one so far that checks all the logical and continuity boxes. I guess we'll find out soon - if so, video confessions are bound to pop up on Youtube soon....