Gold bullion purchases across Asia slowed this week as a long rally in prices discouraged buyers, with traders keeping a close watch on top consumer India ahead of a festival that usually sparks strong demand for the metal.

Also worrying traders was a government plan that would require customers to quote their tax code for major purchases from April 1 as part of a clampdown on so-called "black money", or money earned illegally that has not been taxed. Indian jewellers have already threatened to go on strike over the plan, which would require purchases of over 100,000 rupees ($1,597) to be accompanied by the permanent account number (PAN).