motivation for the Rebenga assassination

If Rebenga was a former communist government official who fell out of favour with fidel castro then what was the motivation for whoever ordered the hit was it communists wanting to silence him, gangsters with a grudge, i know Tony and the people who helped do the hit in the camp had their own motivations of revenge but i am talking about why whomever ordered it, ordered it and there reasoning.

If memory serves me correctly, in one of the Scarface related books that I read, it mentioned that Rebenga was killed on the orders of Frank Lopez who wanted to avenge the torture and death of his brother.

As for Tony's own motivations for killing Rebenga, it was merely so that he and Manolo could get their green cards from Lopez for carving up Rebenga on his behalf.

RE-BEN-GE....RE-BEN-GA........REEEEEBENGAAAAAAA!!!