  We present a near-IR spectroscopic analysis of the intriguing DO white dwarf
RE J0503-285. The IR spectrum fails to reveal evidence of the presence of a
spatially unresolved, cool, late-type companion. Hence we have placed an
approximate limit on the spectral-type and mass of a putative companion (later
than M8, M<0.085Msun). This result rules out ongoing interaction between the
white dwarf and a close companion with M>0.085Msun as responsible for the
discrepancies between the observed photospheric abundances and model
predictions. As the possibility remains that there is a cooler companion lying
beyond the detection threshold of this study we use our modelling to estimate
the improvement in sensitivity offered by a Spitzer observation.
