The head of Venezuelan state-owned PdV's lubricants subsidiary Vassa was arrested for alleged corruption, part of a purge of senior figures associated with outgoing chief executive Manuel Quevedo.
Oscar Rafael Aponte Urdaneta, a retired national guard colonel, is charged with falsifying production and sales data to hide the theft of imported base oils, motor lubricants and sulphuric acid that were later sold abroad.
Aponte's arrest follows the detention of two PdV officials in the company's oil trading and supply division, which is now in the hands of a military figure as part of a series of new senior appointments.
The whereabouts of the detained PdV officials are unclear but their families maintain that they are innocent of the charges.
More arrests are possible as the Sebin military intelligence service investigates associates of Quevedo. But in a sign of his ongoing control of the oil ministry, he is currently attending the Opec+ meeting in Vienna.
Quevedo, a national guard major general who was appointed by President Nicolas Maduro in November 2017, was effectively pushed out of PdV last month in a new managerial overhaul spearheaded by industries minister Tareck El Aissami.
His presumptive replacement is Asdrubal Chavez, who co-chairs the presidential PdV overhaul commission headed by El Aissami. The two figures, who are close to Maduro, are the architects of the company purge, Venezuelan presidential palace and oil ministry officials say.
Aponte is the fourth Quevedo associate jailed or purged from PdV since the commission was set up on 19 February. Most were replaced by more experienced hands, including the new heads of upstream and downstream operations.
Among the appointments is Aissami associate Oswaldo Perez Cuevas as PdV finance vice president. Perez formally headed the government's national development fund (Fonden) which managed some $60bn in Chinese oil-backed loans.
Maduro now wants to fire Quevedo outright for presiding over the industry's decline. But Quevedo has powerful political and military supporters and an outright dismissal could fracture Maduro's military support base, a presidential palace official said. "The generals are unwilling to surrender any of the control they now have within PdV, so Maduro must act cautiously."
Quevedo's supporters within the government include National Constituent Assembly (ANC) president Diosdado Cabello and interior and justice minister Nestor Reverol, a former commander in chief of the national guard.