There's two different types of 'ice beers' that really have nothing to do with each other
1) pis*y tasting lagers that are run through an ice bed to filter some of the yuck. These are the megaswill types that we get here in Canada and the US.
2) German style Eisbock (or Ice Bock in English) which starts out as either a light or dark bock beer running about 8% ABV. After primary fermentation but prior to lagering, the beer is brought down below the freezing point to where the water turns to slush. The beer is then separated from the slush (or vice versa) and the lagering phase is begun. The freezing and slush removal phase can be repeated over and over until the strength, taste and alc.% desired is reached.
I make a batch each winter (and don't care if it's legal or not) by scooping the slush out of the unlagered beer until I've reduced the volume from 23 liters down to 12. I use these volumes simply because that's what size carboys I've got.
The resulting high alc beer gets lagered for at least 6 months then kegged, fermented, bottled and labeled. I call it I, Spock.
Seems to be a favourite with the local beer club and is surprisingly smooth and non-alchoholic tasting for a 12%+ beer.
