Consistent Pauli reduction on group manifolds

We prove an old conjecture by Duff, Nilsson, Pope and Warner asserting that the NS-NS sector of supergravity (and more general the bosonic string) allows for a consistent Pauli reduction on any d-dimensional group manifold G, keeping the full set of gauge bosons of the G x G isometry group of the bi-invariant metric on G. The main tool of the construction is a particular generalised Scherk-Schwarz reduction ansatz in double field theory which we explicitly construct in terms of the group's Killing vectors. Examples include the consistent reduction from ten dimensions on $S^3\times S^3$ and on similar product spaces. The construction is another example of globally geometric non-toroidal compactifications inducing non-geometric fluxes.