Julio Borges, designated by Venezuelan opposition leader Juan Guaido as his chief overseas envoy, told reporters that the gold was refined in Mali and then resold primarily in the United Arab Emirates (UAE) to allow for Maduro’s administration to obtain the equivalent of at least $1 billion in euros ($1.21bn).

The US, which accuses Maduro of rigging his 2018 re-election, imposed sanctions on Venezuela’s state oil company in early 2019 in a bid to pressure Maduro to resign. His socialist government has increasingly turned to the sale of monetary gold as a source of income, with central bank reserves dropping to a 50-year low.

“We are requesting that US and European authorities make their system for dismantling these types of organised crime groups more sophisticated,” Borges said, adding that the opposition had been tracking the Venezuelan gold trade for the past year, culminating in the report presented Wednesday.

Borges said that Noor Capital – an Emirati company that in early 2019 said it had bought three tonnes of gold from Venezuela’s central bank but would refrain from further transactions until Venezuela’s situation stabilised – had been involved in the 2020 transactions.

Noor Capital did not immediately respond to a request for comment on Wednesday. Noor had said in January 2019 that its purchases of Venezuelan gold were in accordance with “international standards and laws in place” as of January 21 of that year.

Reuters news agency could not independently verify Borges’s assertions. One person close to the Venezuelan government said that much of the gold leaving the country was destined for the UAE after two stops, but did not provide further details.