i got the same problem,this is the solution(it seems working):
load your package in R before using Matlab
type evalR('library("bcp")') in Matlab and it should work
i got another problem,i got the following message:
Invoke Error, Dispatch Exception: La classe source de l’objet lié a été modifiée
In english:Invoke Error,Dispatch Exception,Source class from object has been modificated
if anyode could help,thanks a lot !