Ive also heard about that but theres another story(dont know if its true) that in 1935 McGurn approached Ricca with the idea of approaching Lucky Luciano to back them in a international drug smuggling ring.McGurn knew about Ricca's good working relationship with Luciano and Lansky.Frank Nitti was the "boss" back than but Ricca was the rising star.But in 1936 McGurn was dead and Luciano went to jail.
I know that the thread topic involves Ricca. But is accepted that Nitti was actively involved with narcotics? I read that Luciano and Nitti nearly had a war over who had access to the lucrative narcotics market in Hollywood/LA. And that Lucky made an attempt on Nitti's life over that territory.
I'm not 100% sure of the source, but I believe it was from the Johnny Roselli bio, All American Mafioso.