From another site (Brew like a monk)

"Nonetheless, Leffe grabbed a bronze medal as a lager in the recently judged Brewing Industry International Awards in Munich. This is one of the most esteemed international competitions."

It is the fermenation temperature and type of yeast (top or bottom fermenting) that determines the 'lager' title. I believe Leffe is fermented for 2 weeks which, although shorter than some lagers, is considerably longer than most beers.

So I hold up my hands - I don't know which it is realy!

Cheers

DtG