We report on the observation of a narrow resonance in D^*-p and D^*+ \bar p invariant mass combinations in deep-inelastic ep scattering at centre-of-mass energies of 300 and 320 GeV at HERA. The mass of the resonance is measured to be 3099 \pm 3 (stat.) \pm 5 (syst.) MeV, the Gaussian width of 12 \pm 3 (stat.) MeV is compatible with the experimental resolution. The state can be interpreted as an anti-charmed baryon with minimal constituent quark composition uudd\bar c, together with the charge conjugate.

PACS numbers: 14.20.Lq, 14.80.--j