We present early WHT ISIS optical spectroscopy of the afterglow of gamma-ray burst GRB 050730 .
The spectrum shows a DLA system with the highest measured hydrogen column to date : N ( H I ) = 22.1 \pm 0.1 at the third-highest GRB redshift z  = 3.968 .
Our analysis of the Swift XRT X-ray observations of the early afterglow show X-ray flares accompanied by decreasing X-ray absorption .
From both the optical and the X-ray spectra we constrain the dust and gas properties of the host galaxy .
We find the host to be a low metallicity galaxy , with low dust content .
Much of the X-ray absorbing gas is situated close to the GRB , whilst the HÂ I absorption causing the DLA is most likely located further out .