Accused Okpala James, 28, was arrested on July 10 by Crime Branch sleuths when he visited the MCD Civic Centre area, at Minto Road in central Delhi, to deliver cocaine to some clients.
Police said 310 gm of cocaine, valued at Rs 3.5 crore in the international market, was seized from his possession.
"He came to India in April 2015 on a medical attendant visa and got involved in drug smuggling after meeting another Nigerian national Chi Chi B.," Joint Police Commissioner (Crime Branch) Ravindra Yadav said.
James used different mobile phones for his illegal business, police said.
A case under the Narcotic Drugs and Psychotropic Substances Act was registered against James.