The innermost regions of massive protostars traced by masers, high-resolution radio continuum, and near-infrared imaging

Whether high-mass stars (M > 7M_⊙) emerge from a scaled-up version of the low-mass star formation scenario, i. e. through disk-mediated accretion, is still debated. We present the first results of an observational programme aimed to map the innermost regions of high-mass stellar objects by combining together high-spatial resolution maser and radio continuum observations, and near-infrared imaging.