The head of Petroleos de Venezuela SA (PDVSA) has been appointed the country’s new oil minister to oversee a corruption inquiry at the state-run oil company.

Pedro Rafael Tellechea takes over from Tareck El Aissami, who quit on Monday pledging to support the investigation into alleged illicit payments connected to oil exports.

President Nicolas Maduro pictured himself with Tellechea on Twitter as he announced the appointment.

Tellechea was appointed to the top position at PDVSA this year, when he immediately announced an audit into oil supply contracts owing to huge losses after tankers left the country without proper payments being made.

Venezuela — which is sitting on the world’s largest oil reserves — has been forced to turn to intermediaries and the dark fleet to move its cargoes because of US sanctions imposed on PDVSA in 2019.

The government has given few details about the investigation, but US court documents have highlighted alleged illicit payments, fake documents, money laundering and kickbacks for deals involving sanctioned Venezuelan oil.

The US last year announced charges against seven people linked to an alleged Venezuelan oil smuggling racket.

The indictment included details of communications between key players in the plot in which they talked about a “small, aggressive trader” that “conducts high-risk transactions … including with the Venezuelan state-owned company PDVSA, which is under sanctions, [and] has excess profits due to a 40% discount on the selling price of oil”.

More than 20 PDVSA officials have been arrested in recent days as part of the broader corruption probe, according to Reuters, citing sources with knowledge of the inquiry.

Tellechea’s predecessor was personally targeted by US sanctions for alleged links to drug trafficking from his time in other government positions. El Aissami denies the allegations.