CARACAS/HOUSTON (Reuters) - Venezuelan authorities said on Thursday they were seeking an Interpol red alert for ex-oil czar Rafael Ramirez on corruption charges, heightening tensions between the former political heavyweight and the country’s socialist government.

Ramirez, who headed the powerful oil ministry and state energy firm PDVSA [PDVSA.UL] for a decade, is a longtime rival of President Nicolas Maduro who has become more critical of his handling of the economy, now in its fourth year of recession.

State prosecutor Tarek Saab said in a press conference that Venezuela was seeking the arrest of Ramirez for corruption tied to the period when he was commanding the world’s largest crude reserves.

“No crying, citizen Ramirez ... You have been pointed out by all, including by national public opinion, as one of the main embezzlers and culprits of the ... breakdown of PDVSA,” Saab said.

Ramirez’s whereabouts have been unknown since he fled the United States in December, a month after he was ordered to resign as Venezuela’s ambassador to the United Nations over an article he wrote that was seen as an attack on Maduro’s government.

Ramirez denied the corruption allegations.

“I’m going to keep saying what I think. They’re going to burn me like in the Inquisition. But I’m going to continue,” Ramirez told Reuters in a text message.

On Twitter, Ramirez said he was being singled out for putting himself forward for the ruling Socialist Party primaries ahead of a presidential election set to take place before April, in which Maduro is the leading candidate.

“They want to impose a candidate through fear and force, silencing and criminalizing criticism.”

Interpol did not immediately respond to a request for comment on whether it had been requested to arrest Ramirez and whether it would comply.

Insiders say accusations against Ramirez stem from a turf war within the Socialist Party rather than a real desire to root out graft.

The political opposition says Ramirez is a hypocrite who is also responsible for an economic meltdown marked by widespread shortages of food and medicine, the world’s highest inflation rate, and a surge in emigration.

They say he destroyed PDVSA by filling the company with political loyalists and letting at least $11 billion go “missing” during his tenure.