Venezuelan opposition leader and self-proclaimed interim President Juan Guaido speaks to the press in Caracas, Venezuela, Sept 16, 2019. (ARIANA CUBILLOS / AP)

CARACAS - Venezuelan opposition leader Juan Guaido has accepted the resignation of his Miami-based adviser Juan Rendon, his press team said on Monday, after Rendon acknowledged discussions with a US security firm to topple President Nicolas Maduro.

Guaido has denied any involvement in the bungled invasion. But it has raised doubts about his leadership some 16 months since he first declared a rival presidency and denounced Maduro as a usurper who had overseen a six-year economic collapse

Guaido thanked Rendon and another exiled lawmaker, Sergio Vergara, who also resigned from the opposition’s “crisis strategy commission,” for their “dedication and commitment to Venezuela,” without giving a reason for the decision.

Rendon has said that while he negotiated an exploratory agreement with Florida’s Silvercorp USA late last year, he cut ties with the firm’s chief executive, Jordan Goudreau, in November.

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Goudreau, Rendon said, then went ahead with an operation led by two ex-U.S. soldiers to capture Maduro. The plot failed and Venezuelan authorities said security forces killed eight members during one May 3 incursion attempt and arrested a dozen more, including the two US citizens, the following day.

Guaido has denied any involvement in the bungled invasion. But it has raised doubts about his leadership some 16 months since he first declared a rival presidency and denounced Maduro as a usurper who had overseen a six-year economic collapse.

In the statement, Guaido’s press team said Rendon and Vergara “ratified their support for the democratic cause... and called for all national and international sectors to reinforce their support for the interim president.”

Rendon and Vergara confirmed their resignations in public letters. Rendon said the commission had never been interested in “participating in violent activities,” while Vergara said he had not been aware of the so-called Operation Gideon.

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Goudreau, in media interviews, has confirmed his role organizing the incursion.

On Friday, Venezuela Chief Prosecutor Tarek Saab said his office had requested the extradition of Goudreau, Rendon and Vergara for their involvement in the “design, financing, and execution” of the plan.

Meanwhile, a worker at Venezuelan state-oil company Petroleos de Venezuela’s (PDVSA) maritime unit was arrested after criticizing President Nicolas Maduro in a meeting with company leadership, according to a union leader and a person present at the meeting.

Eudis Girot, the executive director of Venezuela’s FUTPV oil workers’ union, said in a statement on Monday that Bartolo Guerra - a tugboat captain with 24 years of experience at PDV Marina, the unit- was arrested on Friday by military counterintelligence officials following the Wednesday exchange.

“We demand his immediate release,” Girot said. “All he did was tell the truth about the inhumane conditions in which they work, and the corruption that engulfs not just PDV Marina, but all of PDVSA.”

Prosecutors have accused Guerra of treason, Girot said.

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Neither PDVSA nor Venezuela’s oil or information ministries immediately responded to requests for comment. Reuters has not been able to verify if Guerra was arrested or his current whereabouts.

At the meeting with PDV Marina’s new chief, Cesar Romero, workers voiced concerns about low salaries, poor working conditions, and worries that PDVSA would sell its stake in the company, in line with a proposed restructuring, said the person present, who spoke on the condition of anonymity.

During the meeting, Guerra said he had been working for 40 consecutive days without a day off, and that the company had not provided food or water for employees in a week, said Girot and the person present. He ended by blaming the situation at the company on Maduro and the socialist national government, they said.

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Romero assumed the leadership of PDV Marina after its prior president, Oswaldo Vargas, was arrested in March on accusations by the government of fuel smuggling, part of a broader purge at PDVSA. Opposition politicians have denounced widespread corruption at PDVSA, once the engine of the OPEC nation’s economy. The state-run firm has suffered from acute cash flow issues and an exodus of qualified personnel in recent years as its crude output has plummeted.

Maduro insists his government is committed to combating corruption, and argues that US sanctions on the company - part of Washington’s strategy to oust him from power - are the cause of its more recent struggles.