The infrared behaviour of the gluon propagator is important for an understanding of confinement. Previous conjectures range from a strong divergence [1] to a propagator that vanishes in the infrared [2,3]. Lattice QCD should be able to resolve this issue by first-principles, model-independent calculations. However, previous lattice studies [4,5] have been inconclusive since they have not been able to access sufficiently low momenta. Here we will report results using an asymmetric lattice with a spatial length of 3.3 fm This gives us access to momenta as small as 400 MeV.