Neeraj Bali Chandigarh, Oct 31(UNI) India''s Enforcement Directorate (ED) has arrested a close associate of the alleged mastermind behind a cryptocurrency investment fraud involving more than 2.48 lakh users and estimated investor losses of Rs 500 crore, following searches across Chandigarh, Mohali and Zirakpur that led to the seizure of Rs 72 lakh in cash.