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The spectrum of the MeV tail detected in the black-hole candidate Cygnus X-1remains controversial as it appeared much harder when observed with theINTEGRAL Imager IBIS than with the INTEGRAL spectrometer SPI or CGRO. Wepresent an independent analysis of the spectra of Cygnus X-1 observed by IBISin the hard and soft states. We developed a new analysis software for thePICsIT detector layer and for the Compton mode data of the IBIS instrument andcalibrated the idiosyncrasies of the PICsIT front-end electronics. The spectraof Cygnus X-1 obtained for the hard and soft states with the INTEGRAL imagerIBIS are compatible with those obtained with the INTEGRAL spectrometer SPI,with CGRO, and with the models that attribute the MeV hard tail either tohybrid thermal/non-thermal Comptonisation or to synchrotron emission.

Observations of Cygnus X-1 in the MeV band by the INTEGRAL imager