Once it became clear that prime ministers Putin and Tymoshenko had decided to cut RosUkrEnerho out of their two countries' gas business to settle the most recent gas spat, Dmitro Firtash and Ivan Fursin, who own half of RUE were finished. [The other half of RUE is owned by Gazprom.]
On 29th January this year arrest warrants had allegedly been issued by the investigative committee of the RF prosecutor's office. According to investigators the two businessmen were taking refuge in Ukraine and were refusing to appear as witnesses in a case concerning Semyon Mogilevich.
Whatever the validity of their claim to their portion of RUE's gas stored in Ukraine, they have been 'hung out to dry' [abandoned when in trouble] by their RUE partners.
One respected Ukrainian investigative journalist says: "Everything is leading to Firtash being caught by the Russian FSB security services and locked up: and all of his assets, which the Ukrainian SBU security services are defending, will be confiscated [to benefit] the Russian budget."
The raid on Naftohaz's offices last week was a blunder. Yushchenko's control over the SBU has now been weakened.