New Delhi, Nov 18 (ANI): President Pranab Mukherjee, said that unaccounted money on which tax is not paid has a pernicious impact on economy. Prime Minsiter Narendra Modi had promised his government would change laws or enact new measures to bring back such funds. On taking office, he appointed a panel to investigate the matter. Mukherjee said nexus between black money, militancy and drug trafficking posed a great threat to global peace.