How about they rented a local sailboat, and shipped their equipment in a container as household goods to their new Swedish home?
Maybe I’m a bit more of a criminal than you guys reading this, but that is all not that hard to do.
The rental of the boat....leads to a mailbox situation. The supposed owner of the ‘company’ knew nothing much about boats when German cops questioned her, and the real ownership appears to lead back to the Ukraine (I saw that two weeks ago in German newspapers).
No, it’s not hard, I agree.
It’s a fragile and vulnerable system, whose location was known to the world, in relatively shallow water.
Any state actor and lots of non state actors could do this.
The only question is who was motivated to do to?
That’s most likely the USA and Ukraine.