Tycoon is found after eight months missing... with 'thief' carved into his forehead

Russian gangsters and Irish terrorists do like their property, and it's possible they were in contact with/used some branch of the IRA to abduct him, but you'd have to take anything he said with a pinch of salt even now.

If he'd said one or the other, I might have believed it. But both, doing a joint kidnapping with joint personnel? Sounds a bit farfetched.

You'd be surprised. The Russians sold kit to both sides over here, though that wasn't yesterday. The Israelis assisted the loyalists for information on missile tech (we're surprisingly knowledgeable there ) and targeting pro-Palestinian groups with alleged Provo links (they got a lot of kit off Gadaffi who wasn't on Israel's Xmas card list). Loyalist weapons from South Africa, dissident republican weapons from Lithuania (that's an ongoing case IIRC)...

Murky isn't the word; the links go from personal vendettas through money making, to straight up terrorism

Russian gangsters could probably do it on their own, but they would probably use Chechens to extract what ever information that they need. He would probably not have been dumped unless they need him alive for some reason. The Russians are pretty brutal on their own. In Spain where my parents had a second home, an estate agent had a Russian visitor who bought a house with cash, and when the man returned to collect the deeds the agent denied receiving any cash. The Russian left and a few days later on a Friday night as he was closing up two men entered and killed him. He was found a few days later hanging from a meat hook in his office. He died very slowly hanging from that hook.

Darwin award.

Unless he had already procreated. To actually rip off a Russian is definitely a Darwin event.