The British company that provided voting machines used in Venezuela's election this week said Wednesday that the balloting was "tampered with" and that the company could not endorse the results.
"We estimate the difference between the actual participation and the one announced by authorities is at least 1 million votes," said Antonio Mugica, chief executive of Smartmatic.
Mugica did not specifically accuse the government of President
He declined to provide specific figures, saying that the tally was still under review. He added that the fact that the opposition did not send monitors to polling places to check vote counts facilitated the manipulation of results.
Smartmatic's disclosure bolstered the claims of some observers who said Sunday that exit polling indicated that the government's turnout figures were inflated.
The National Electoral Council on Wednesday denied any implication of ballot manipulation, criticized Smartmatic's comments as "irresponsible" and threatened legal action against the company.
"The worst is that Smartmatic participated in all the audits," the council said in a statement. "Whatever manipulation such as that indicated by Mugica would ignore the fact that Smartmatic is part of the security of the tallying system."
The council said late Sunday that 8.1 million voters, or 41.5% of those eligible, turned out to select 537 members of a new assembly charged with writing a new constitution.
The turnout figure as stated by the government was significant because it exceeded the 7.6 million ballots cast by opposition voters on July 16 in a protest vote to express rejection of the assembly. By apparently winning the turnout contest, Maduro government could thus claim greater public approval.
Leaders of the opposition-controlled National Assembly say the new constitution is a maneuver by Maduro to sideline the democratically elected congress and perpetuate himself in power. Several international leaders and human rights groups also have criticized the new constitution as a prelude to dictatorship.
This week, the United States announced it was levying sanctions on Maduro by freezing any U.S. assets he has, a measure imposed on 13 other members of his government last week. Washington is also said to be considering restricting imports of crude oil from Venezuela, among the top U.S. suppliers.
Opposition lawmaker Julio Borges, who is president of the National Assembly, told reporters Wednesday that the Sunday vote was a fraud and that he and other leaders would register complaints with the nation's attorney general, who functions as a public advocate.
"The assembly election was not only a fraud in being called in the first place, but all the results given by the National Electoral Council were fraudulent," Borges said.
The controversy arose shortly before the 537 assembly members were to be sworn in at an arena in south Caracas on Wednesday afternoon. The body is to commence its work drafting a new constitution on Thursday at the Federal Legislative Palace, home to the National Assembly.
But majority members of the National Assembly led by Borges insist that they are the legitimate legislators and that they will take their seats at the palace as they normally do.
Venezuela has been in the throes of nationwide protests since late March, with citizens demonstrating against food shortages, galloping inflation and Maduro's autocratic government. Clashes with authorities have left 120 dead and thousands injured.
Meanwhile, fissures among Maduro supporters were apparent late Tuesday when three assembly members announced they were abandoning the president's United Socialist Party of Venezuela, or PSUV, to form a dissident bloc in congress.
"We have decided to form the Socialist Parliamentary Bloc, inspired by the necessity to contribute solutions required by the country's great problems," said Assemblyman Eustoquio Contreras in a speech during a legislative session. He was joined by lawmakers Ivonne Tellez and German Ferrer, who is the husband of Atty. Gen. Luisa Ortega Diaz, also a Maduro critic.
Also on late Tuesday, the British Foreign Ministry said family members of diplomatic staff in Venezuela have left the country because of security concerns. The United States made a similar precautionary move last month.
Across the border in Colombia, governors of three frontier states expressed concerns over the masses of Venezuelans seeking refuge, telling El Tiempo newspaper that local governments were unable to cope with the demand for health, housing and other services. As many as 30,000 Venezuelans a day have entered over the last week, officials have said.
Special correspondents Mogollon and Kraul reported from Caracas and Bogota, Colombia, respectively.