The current invention provides a hydrotreating catalyst comprising of metals of at least one each from Group VIB, preferably molybdenum and Group VIII, preferably nickel, of the periodic table supported on alumina modified with small amounts of modifying elements well dispersed on the surface so as to retain the physico-chemical characteristics of the support and result in high performance for hydrodesulphurization catalyst, and a commercially viable process for producing such a catalyst. The present invention also discloses a commercially viable method for modifying alumina in the powder form without affecting the porous structure of the support obtained.