We present Chandra observations of the enigmatic galaxy IRAS00317-2142 , which is classified as a star-forming galaxy on the basis of the ionization level of its emission lines .
However , a weak broad H \alpha wing and a high X-ray luminosity give away the presence of an active nucleus .
The Chandra image reveals a nuclear point source ( L _ { ( 2 - 10 keV ) } \sim 6 \times 10 ^ { 41 } erg~ { } s ^ { -1 } ) , contributing over 80 % of the galaxy X-ray counts in the 0.3-8 keV band .
This is surrounded by some fainter nebulosity extending up to 6 kpc .
The nucleus does not show evidence for short-term variability .
However , we detect long term variations between the ROSAT , ASCA and Chandra epoch .
Indeed , the source has decreased its flux by over a factor of 25 in a period of about 10 years .
The nuclear X-ray spectrum is well represented by a power-law with a photon index of \Gamma = 1.91 ^ { +0.17 } _ { -0.15 } while the extended emission by a Raymond-Smith component with a temperature of \sim 0.6 keV .
We find no evidence for the presence of an Fe line .
The nucleus is absorbed by an intrinsic column density of N _ { H } \sim 8 \times 10 ^ { 20 } cm ^ { -2 } .
Thus the Chandra observations suggest that at least the X-ray emission is dominated by a type-1 AGN .
Then the observed optical spectrum can be explained due to the masking of the nucleus by the powerful star-forming component .
These together with previous X-ray observations of galaxies with no clear signs of AGN activity in the optical , ( eg NGC6240 ) cast doubt on the optical classification scheme and have implications for the nature of the ’ normal ’ galaxies detected in deep Chandra X-ray surveys .