Image copyright Getty Images Image caption Vice-President Tareck El Aissami approved the transfer in 2016, before being accused of corruption by the US in 2017
It was part of a plot to steal $1bn (£740m) of oil revenue.
Four directors of Venezuelan state-owned PDVSA were convicted on Monday for their role in a scheme to steal from PDVSA.
But there are few answers why they were jailed.
While the directors enjoy access to state employees, much of their earnings come from international bankers.
They charge a fee for managing oil field contracts from companies outside Venezuela, but the money goes straight into their bank accounts.
Swiss-based commodities trading giant Glencore, which has since left the country, is among these international banks.
What is PDVSA?
Before being nationalised by Hugo Chavez in 1999, PDVSA was the state company that imported gasoline, oil and other products into Venezuela.
When he died, President Nicolas Maduro, who succeeded him, announced his oil industry would be a single company, run by Venezuelans who would be trusted with the national resources.
Many of the senior executives who started the reorganisation but are still at the helm have fled to international banking centres, where they can be supported by the lines of generosity that pervade the banking system.
PDVSA in particular has managed to avoid the real-world consequences of sanctions, on which US President Donald Trump has imposed a set of measures that cut Venezuela off from the rest of the world’s bank system.
What is happening in Venezuela?
A team of US diplomats shuttled from Caracas to the Caribbean over the weekend, with the aim of securing a prisoner swap between the Venezuelan government and jailed government opponents.
The measure was taken after former vice-president Tareck El Aissami was slapped with fresh US sanctions earlier this month.
Mr El Aissami, already charged by the US government with drug trafficking, is accused of being part of a network that moved suitcases of cash out of Venezuela to secure influence in the United States.
Last week, the US announced more sanctions against Venezuela’s long-standing nemesis Russia, which the US suspects of supporting the country in return for access to Venezuela’s vast oil reserves.