  We present here the first convincing observational manifestation of a
magnetar-like magnetic field in an accreting neutron star in binary system -
the first pulsating ultra-luminous X-ray source X-2 in the galaxy M82. Using
the Chandra X-ray observatory data we show that the source exhibit the bimodal
distribution of the luminosity with two well-defined peaks separated by a
factor of 40. This behaviour can be interpreted as the action of the "propeller
regime" of accretion. The onset of the propeller in a 1.37 s pulsar at
luminosity of ~$10^{40}$ erg/s implies the dipole component of the neutron star
magnetic field of ~$10^{14}$ G.
