We present in this paper optical and X-ray follow up observations for three X-ray selected objects extracted from the ROSAT North Ecliptic Pole survey which is a flux-limited , completely identified survey .
All three objects have X-ray luminosities in the 10 ^ { 44 } erg s ^ { -1 } regime and show narrow emission lines in their optical discovery spectra , typical of QSO 2 type objects .
Spectroscopic data for the three QSO 2 candidates , obtained with the Telescopio Nazionale Galileo , confirm the widths of the H \alpha or H \beta emission lines are less than 750 km s ^ { -1 } .
On the other hand XMM- Newton data do not show any sign of obscuration as expected for this class of objects .
The X-ray spectra of the three objects are all well fit by a single power law model with \Gamma \sim 1.7 with low energy absorption fixed to the Galactic value along the line of sight to each object .
Most observational evidence supports the scenario where optical and X-ray obscurations are linked , contrary to our findings .
We discuss the unanticipated results of these observations , and compute the space density in soft X-ray surveys of this possibly new class of objects .
Their spatial density in the ROSAT NEP survey is 2.8 ^ { +2.7 } _ { -1.5 } \times 10 ^ { -8 } h ^ { 3 } Mpc ^ { -3 } in a \Lambda CDM model with h = 0.7 .
Unobscured QSO 2 candidates could go unrecognized in current X-ray surveys where the low hydrogen column density is inferred by a hardness ratio rather than a more precise X-ray spectrum measurement .