We present the first unambiguous evidence of a broad ( Gaussian width \sim 330 eV ) component of the iron K _ { \alpha } fluorescent emission line in the X-ray obscured Narrow Line Seyfert 1 Galaxy NGC 5506 .
This is the main results of a spectroscopic monitoring campaign on this source performed with the XMM-Newton observatory between February 2001 and January 2009 .
The broad line lacks extreme redwards skewness .
If modelled with a relativistic component , the profile of the line is consistent with a flat emissivity radial dependence ( \alpha \simeq 1.9 ) .
The disk inclination ( \simeq 40 ^ { \circ } ) is nominally larger then typically observed in unobscured AGN , in agreement with most measurements of broadened iron lines in Seyfert 2 galaxies .
The quality of the data allows us to decompose the full iron emission line complex , and to study its long-term ( timescales of weeks to years ) variability pattern .
The intensity of the neutral and narrow iron K _ { \alpha } core remains constant during the monitoring campaign .
This indicates that the optically thick gas responsible for the non-relativistic reprocessing of the primary AGN continuum in NGC 5506 is probably located in the torus rather than in the optical Broad Line Region .