We present spectroscopic and photometric data of the peculiar SNÂ 2001gh , discovered by the Southern inTermediate Redshift ESO Supernova Search ( STRESS ) at a redshift z=0.16 .
SNÂ 2001gh has relatively high luminosity at maximum ( M _ { B } = -18.55 mag ) , while the light curve shows a broad peak .
An early-time spectrum shows an almost featureless , blue continuum with a few weak and shallow P-Cygni lines that we attribute to He i .
He i  lines remain the only spectral features visible in a subsequent spectrum , obtained one month later .
A remarkable property of SNÂ 2001gh is the lack of significant spectral evolution over the temporal window of nearly one month separating the two spectra .
In order to explain the properties of SNÂ 2001gh , three powering mechanism are explored , including radioactive decays of a moderately large amount of ^ { 56 } Ni , magnetar spin-down , and interaction of SN ejecta with circumstellar medium .
We favour the latter scenario , with a SN Ib wrapped in a dense , circumstellar shell .
The fact that no models provide an excellent fit with observations , confirms the troublesome interpretation of the nature of SNÂ 2001gh .
A rate estimate for SNÂ 2001gh-like event is also provided , confirming the intrinsic rarity of these objects .