MIAMI -- A Venezuelan electoral official has denounced what he calls a “grave lack of transparency” in last month's presidential vote in which Nicolás Maduro was declared the winner despite evidence he was trounced by the main opposition candidate.

Juan Carlos Delpino, one of five members of the National Electoral Council, or CNE in Spanish, was the only one who had indicated a willingness to oppose the wishes of Maduro's government before the vote.

On Monday, he published a letter on social media detailing several alleged irregularities occurring both before and during the July 28 election. He asserted that polling stations were slow to report results from automated voting machines while several opposition volunteers were removed, in violation of electoral rules guaranteeing the transparent transmission of tallies to CNE headquarters.

Delpino stated that he was informed that the hourslong delay was caused by a purported hacking of the CNE platform and that only 58% of results had been gathered. In protest, he decided not to join his fellow council members in monitoring the vote count from the CNE data hub or attending the midnight press conference when CNE President Elvis Amoroso, a ruling party loyalist, declared Maduro the victor.

“I deeply regret that the results do not benefit the Venezuelan people, that they don't help bridge our differences or promote national unity but instead create doubt among the majority of Venezuelans and the international community,” Delpino wrote.

His letter comes as Maduro reiterates his claim that he won re-election by over 1 million votes. His government has disregarded calls from the U.S., European Union and even leftist allies from Brazil, Colombia and Mexico to release the voting records that would support such assertions.

Meanwhile, the opposition has published online what it claims are tallies from 80% of polling machines showing that its candidate, Edmundo González , won by a margin of more than 2 to 1.

Last week, the Venezuelan Supreme Court certified the results and claimed that the voting tallies published online by the opposition were fabricated. Authorities have demanded that González testify in a criminal investigation regarding alleged attempts to incite panic in the South American nation by challenging the results.

Former diplomat González and his main supporter, opposition leader Maria Corina Machado, went into hiding after the election as security forces arrested over 2,000 people and cracked down on demonstrations across the country protesting the results.

Delpino, in an interview with The New York Times published Monday, also said he had gone into hiding.

His letter also highlighted what he called a number of irregularities in the CNE's decisions, including a lack of meetings before the vote that made it difficult to establish clear rules for campaign poll workers, international observers, and millions of Venezuelans living abroad.