  We here report the detection of extended HeII4686 nebular emission in the
central region of NGC1569 using the integral field spectrograph MEGARA at the
10.4-m Gran Telescopio Canarias. The observations cover a Field of View (FoV)
of 12.5 arcsec x 11.3 arcsec at seeing-limited spatial resolution of ~15 pc and
at a spectral resolution of R=6000 in the wavelength range 4330--5200 Angstrom.
The emission extends over a semi-circular arc of ~40 pc width and ~150 pc
diameter around the super star cluster A (SSC-A). The Av derived using Balmer
decrement varies from the Galactic value of 1.6 mag to a maximum of ~4.5 mag,
with a mean value of 2.65+/-0.60 mag. We infer 124+/-11 Wolf-Rayet (WR) stars
in SSC-A using the HeII4686 broad feature and Av=2.3 mag. The He+ ionizing
photon rate from these WR stars is sufficient to explain the luminosity of the
HeII4686 nebula. The observationally-determined total He+ and H0 ionizing
photon rates, their ratio, and the observed number of WR stars in SSC-A are all
consistent with the predictions of simple stellar population models at an age
of 4.0+/-0.5 Myr, and mass of (5.5+/-0.5)x10^5 Msun. Our observations reinforce
the absence of WR stars in SSC-B, the second most massive cluster in the FoV.
None of the other locations in our FoV where HeII4686 emission has been
reported from narrow-band imaging observations contain WR stars.
