CARACAS, Venezuela (AP) — Venezuela’s attorney general said Saturday that 21 people, including senior officials in the government of President Nicolás Maduro and business leaders, have been arrested in connection with a corruption scheme involving international oil sales.

Prosecutor Tarek William Saab said the alleged scheme involved selling Venezuelan oil through the country’s cryptocurrency oversight agency in parallel to the state-run Petróleos de Venezuela SA.

The oversight agency allegedly signed contracts for the loading of crude on ships “without any type of administrative control or guarantees,” violating legal regulations, Saab said, without mentioning the amounts involved. Once the oil was marketed, “the corresponding payments were not made” to the state oil company.

The attorney general’s statement comes five days after Venezuela’s once-powerful oil minister, Tareck El Aissami, resigned amid allegations of corruption against some of his closest associates.

El Aissami said he resigned to “accompany and fully support” the investigations. For now, El Aissami, who was one of Maduro’s trusted ministers, is not facing charges.

The US government designated El Aissami a narcotics kingpin in 2017 in connection with activities in his previous positions as interior minister and governor. El Aissami’s resignation was announced two days after the Public Ministry appointed five prosecutors to probe the alleged crimes investigated by the National Anti-Corruption Police.

Among the 10 officials arrested, according to the attorney general, are Colonel Antonio Pérez Suárez, the vice president of trade and quality supply at PDVSA; Hugbel Roa, the former minister of food; and Joselit Ramírez, the national superintendent of cryptocurrencies.

Also arrested were 11 businessmen, who will be charged with appropriation or diversion of public assets, influence peddling, money laundering and criminal association, Saab said, adding that the crime of treason against the country will be added to public officials’ charges.

Corruption has long been rampant in Venezuela, which sits atop the world’s largest petroleum reserves. But officials are rarely held accountable — a major irritant to citizens, the majority of whom live on $1.90 a day, the international benchmark of extreme poverty.