The US State Department is facing mounting pressure to disclose how much oil revenue it has collected from Venezuela and how those funds are being managed. Nine months after asserting control over Venezuelan oil exports, the administration has not revealed the total collected or amounts returned to the interim government in Caracas. The Government Accountability Office (GAO) has been investigating since July, but the department has yet to meet with the watchdog.

Top Democrats, including Joaquin Castro, are threatening subpoenas if their party wins the November midterms. In April, the State Department said KPMG was auditing the accounts and reports would be shared with Congress, but none have been provided. Castro and other Democrats requested the KPMG reports by October 8.

The FT calculated at least $13bn in revenues collected by July. Lawmakers from both parties also want to see the Pentagon's contract with Venezuelan businessman Alejandro Betancourt, which could give the US a 35 per cent stake in his oil business. The State Department says it responds to oversight requests and disburses funds per the interim government's direction. President Donald Trump has claimed the US is profiting from its involvement, fueling speculation that some funds are being retained.