(Bloomberg) -- Venezuelan authorities stepped up arrests and stripped the immunity of a ruling party lawmaker on Tuesday as part of a widening corruption probe that has shaken the top ranks of the ruling socialist party. 

So far 19 people have been detained, with more arrests to come, according to Jorge Rodriguez, head of the government-controlled National Assembly. 

“This investigation is just beginning,” Rodriguez said, during a parliamentary session broadcast by state TV. “The time for justice has arrived.”

President Nicolas Maduro late Tuesday named Pedro Tellechea, head of the state oil company PDVSA, as new oil minister, following the resignation of Tareck El Aissami on Monday amid the corruption probe. Maduro said on Twitter that Tellechea’s appointment was made amid a “transformation process” in the oil industry. 

El Aissami resigned saying that he would cooperate with the investigation, though he hasn’t been formally accused of anything. 

Read more: Venezuela’s Oil Minister Resigns Amid PDVSA Corruption Probe

Judges, elected officials and the head of the crypto oversight agency have been detained so far. Venezuela is the most corrupt country in the Americas, according to an annual index published by Transparency International, which campaigns to promote clean government.

Ruling party lawmaker Hugbel Roa had his parliamentary immunity taken away by the National Assembly, to enable his trial. 

Roa, a former technology minister, had a key role in promoting the Petro, the sovereign cryptocurrency proposed by the government to get around US attempts to restrict Venezuela’s access to the global financial system. Roa traveled to Qatar and elsewhere seeking backers for the project. 

Joselit Ramirez, head of the authority in charge of regulating crypto currencies was also arrested, state TV said Monday. 

Reuters reported on Tuesday that the state oil company is owed billions of dollars, after it turned to intermediaries when US sanctions imposed in 2019 made it difficult to sell oil through normal channels. 

‘Grave Corruption’

On Sunday, Venezuela’s public prosecutor said it had opened the investigation after the anti-corruption police’s flagged “grave administrative corruption and embezzlement” involving a large group of people. 

The current government has been in power since 1999, led first by Hugo Chavez then, since 2013, by Maduro. Even so, Rodriguez said he hoped the investigation would also bring to justice “opposition figures who stole the assets of the people of Venezuela”. 

Venezuela holds presidential elections in 2024, with Maduro likely to run as the government’s candidate, for a third six-year term. The opposition will choose a single candidate to confront him in primaries to be held Oct. 22.

(Updates with naming of Pedro Tellechea as oil minister in fourth paragraph.)

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