If the ship is indeed Ukrainian and if the tanks were sold by Ukraine, the Russians certainly don't have anything to do with it. US might, however, but I strongly doubt it.
On the other hand, Ukraine is a land of Mafia (what we usually call Russian mafia is more often Ukrainian) and these guys might well be involved. Moreover, the Ukrainians are big enough to do their crap all by themselves.
Whatever, this a kind of messy situation that is open for imagination.