Just a couple of months ago, Alejandro Betancourt was effectively confined to his luxury London residences, facing potential extradition to Switzerland over allegations of embezzlement and money laundering. But now the Venezuelan millionaire is set to be a key player in “the biggest oil deal in world history”, according to US President Donald Trump. Read moreTrump announces 'historic' agreement for US stake in Venezuela oil reserves Trump’s 'viceroy' in Venezuela? It is very difficult to get a clear picture of the deal between Washington and Caracas announced by Trump on Friday because there is "no publicly available text of any agreement so far", said Tom Long, a Latin America specialist at the University of Warwick. He added that the "Venezuelan government is being very careful not to publicly contradict the very expansive but probably incorrect claims that begin on social media". But what we know about the deal seems ambitious because it grants the US the right to exploit “nearly 20 percent of Venezuela’s proven reserves – that is 17 oil fields where production is supposed to be increased”, explained Thomas Posado, a Venezuela specialist at the University of Rouen. That amounts to 65 billion barrels from the South American country. Venezuela’s Interim President Delcy Rodriguez said that this agreement is expected to bring $100 billion in investments to her country. However, “the practical details of implementation and the reality of future investment” remain very unclear, Posado added. The identity of Washington's alleged Venezuelan partner in exploiting the oil fields was only officially confirmed on Tuesday. US media outlets last week named 46-year-old Betancourt, the controversial Venezuelan oil tycoon, as the new intermediary between Washington and the Venezuelan government. The Financial Times even went so far as to describe him as "Trump’s ‘viceroy’ in Venezuela". Trump is banking on Betancourt being “a key player in the Venezuelan oil sector who appears to have the trust of Delcy Rodriguez", according to Long, adding that this position was previously "really dependent on relationships with the state". Betancourt is the head of North American Blue Energy Partners (NABEP), Venezuela’s second-largest private oil producer. Rodriguez has reportedly consulted him on several occasions for advice on the best way to revive Venezuela’s economy, according to several investigations by Spanish-language media outlets.