Infrared spectroscopy of V404 Cygni: limits on the accretion disc contamination

We have obtained for the first time 2.10–2.45 ¼m infrared spectra of the soft-X-ray transient V404 Cygni. We determine a 95 per cent confidence upper limit to the fraction of light arising from the accretion disc of 14 per cent. The effect this has on the mass of the compact object, determined from modelling the infrared ellipsoidal variations, is to reduce its mass to at most 10 M⊙.