The opposition immediately raised objections that the Prosecutor's Office would not conduct an independent investigation because its head was appointed by parliament, which is dominated by the Georgian Dream ruling party.

Georgian Dream, which has deepened the country's ties with Russia, declared victory in Saturday's election after authorities said it won about 54 per cent of the vote with almost all ballots counted. The balloting was seen by many Georgians as a choice between continuing to support the ruling party or seeking closer integration with the European Union.

European observers said the election took place in a “divisive” environment marked by intimidation and instances of vote-buying, double voting and physical violence. Georgian observers also reported multiple violations and said the results do not reflect “the will of the Georgian people.”

The United States and the EU have called for a full and transparent investigation of the alleged violations.

Thousands of people rallied outside the parliament building Monday night to hear opposition speakers, including President Salome Zourabichvili, denounce what they called a stolen election.

The nation of 3.7 million people, which lies between Russia and Turkey, was granted the status of an EU candidate in 2022, but Brussels halted the process indefinitely after the parliament, dominated by Georgian Dream, adopted a “foreign influence law,” similar to ones enacted in Russia to crack down on dissent.

The party was set up by Bidzina Ivanishvili, a shadowy billionaire who made his fortune in Russia and served briefly as Georgia's prime minister but has stayed out of public view since 2013.

The investigation was requested by the Central Election Commission, and Zourabichvili was summoned for questioning Thursday about the allegations; others “who may possess information related to the alleged criminal act” also would be questioned, the Prosecutor's Office said.

Election officials also have announced a partial recount of ballots cast at a number of polling stations, aimed at addressing some of the accusations. It wasn't immediately clear when that will be completed, with a CEC statement saying ballots from five polling stations randomly selected in each election district will be recounted.

But Salome Samadashvili of the opposition Strong Georgia coalition, questioned whether the Prosecutor's office was independent of Ivanishvili's influence.

“If somebody thinks that they can fool the Georgian people or our international partners into believing that Bidzina will investigate his own election fraud, they are mistaken. Nobody can be fooled,” Samadashvili said.

“That is why we are saying that the investigation should be conducted by an international mission with the adequate mandate and qualifications. Until this is done, this election cannot and will not have legitimacy or trust,” she added.

Zourabichvili, who has a mostly ceremonial role as president, suggested that “Russian elections” were held in the country, and said “technology was used to whitewash counterfeiting. Such a thing has never happened before.”

Prime Minister Irakli Kobakhidze, a member of Georgian Dream, urged Zourabichvili to turn over evidence of vote-rigging and concluded that she has none.

“Whether it's Salome Zourabichvili or anyone else, if they have any evidence, they should submit it to the Prosecutor's Office and the relevant authorities instead of making baseless oral statements about events that never happened. This is their responsibility,” he said.

"However, I am certain that, since she has no facts, she won't dare to go to the Prosecutor's Office or provide them with any information regarding the accusations she is making verbally,” Kobakhidze said.