Crude oil exports from Venezuela have all but dried up as the government investigates oil contracts with a mountain of unpaid oil purchase bills to the tune of $21 billion.

According to Reuters, the investigation, which has so far seen at least 20 arrests and the resignation of Venezuela’s oil minister, is now at a stage where invoices for oil sold are being matched with payments made, according to unnamed sources and documents.

While this goes on, state-owned PDVSA is exporting almost no oil with just four buyers scheduled to take off from Venezuelan ports this week: an Iranian company, A Cuban one, Chevron, and a Chinese company.

Earlier this week, PDVSA documents showed that the company had accumulated $21.2 billion in accounts receivable over the past three years. The amount represented some 84% of the oil it had sold during the period, Reuters noted in a report.

The value of Venezuela’s oil exports was $25.27 billion between January 2020 and March 2023. But documents provided to Venezuela’s attorney general during an audit of PDVSA contracts showed that the state oil firm could only confirm the receipt of just $4.08 billion of this.

What’s more, $3.6 billion of the total receivable sum may never get paid as it concerns cargoes whose buyers never prepaid even a part of the total owed for that cargo.

PDVSA is said to have tightened the prepayment rules for its crude oil after the review of contracts began earlier this year. The Venezuelan state-owned oil company now demands that cargoes be paid in cash or in goods and services that should be received before loadings can take place.

In February, Venezuela’s oil exports fell by 8% because of the contract reviews, which have caused loading delays and bottlenecks at Venezuelan ports as vessels were held until payment for the cargo was confirmed before being let go.