In this letter we present clear evidence that Mrk573 is an obscured narrow-line Seyfert 1 (NLSy1) galaxy and not an archetypal Seyfert 2, as it has been classified until now. Only three galaxies have been proposed as members of this class, prior of this work. Here we report near-infrared spectroscopy data taken with LIRIS on the 4.2 m William Herschel Telescope (WHT). Our high quality near-infarred nuclear spectrum in the 0.88-1.35 microns wavelength range shows the permitted OI $\lambda$1.128,1.317 narrow lines, the FeII 9200 $\A$ lines, together with a relatively broad component ($\sim$ 1700 km/s) of Pa$\beta$. These features can originate only in an optically thick high-density region, similar to those observed in the broad line region (BLR)