A Venezuelan prosecutor who helped convict Leopoldo López is seeking asylum in the United States and is calling the opposition leader's trial a "sham" orchestrated by the administration of embattled President Nicolás Maduro.

Franklin Nieves said he had received orders to arrest the former Chacao mayor days before he appeared at an anti-government rally that ensued in violence for which López was eventually blamed, according to a video posted on Monday on the Venezuelan news website La Patilla.

In fact, López was to be taken into custody at a previous demonstrations, but those plans were later canceled when the opposition figure failed to make an appearance at said protest, Nieves detailed.

In an interview with the Wall Street Journal, meanwhile, Nieves apologized for his role in convicting López, who earlier this year was sentenced to spend nearly 14 years in a military prison.

"From my heart, I want to ask for forgiveness from Venezuela, Leopoldo López's, López's wife, the López family, and especially from their children," he said.

The 44-year-old opposition leader should be considered a political prisoner, Nieves added.

"Leopoldo López is innocent," he said. "This was a totally political trial which should be nullified. All of Leopoldo López's human rights were violated because he was not able to present any witnesses or evidence."

Venezuela's chief prosecutor, Luisa Ortega Diaz, denied Nieves' account and accused her former employee of having caved in to foreign interests, the Guardian reported.

"We at the prosecutor's office, we don't put pressure on anyone," Ortega Diaz said.

The attorneys pursuing López's appeal, meanwhile, have already begun to incorporate Nieves' statements into documents they plan to submit to the Caracas Court of Appeals, El Nacional noted.

"We are in the process of transcribing all of the prosecutor's references in both videos, in addition to his statements to the Wall Street Journal, in order to present them in the course of the appeal," said Juan Carlos Gutiérrez, one of the opposition leader's defenders.

"They will be included as new evidence, of which we had no previous knowledge, and will have to be taken into account by the court."