Matthew and I were having a disagreement about whether they burn the coffin as well as the body in a crematorium. I thought not as did Charlie from Scooterworks. Matthew thought they did. However, he was basing his opinion on the scene in a James Bond film when Sean Connery is in a coffin and jets of flame start appearing so probably not too reliable as info.
But the ever reliable Wikipedia has the answer - yes, they do. Burn the coffin too, I mean. It's the law apparently.