The Djumbala club is in the Canarsie section of Brooklyn. Police did not immediately release further information.
While the party had been promoted as the "official" after-party, "Notorious" distributor, Fox Searchlight, said it was not related.
Smalls was born Christopher Wallace and also used the stage name "Notorious B.I.G."
His debut CD, 1994's "Ready to Die," helped re-energize East Coast rap. He was killed in Los Angeles in 1997.