A former confidant of Georgia’s most powerful man has alleged in a Tbilisi court that he was “kidnapped from abroad” last Saturday and flown back to Georgia by force.

Giorgi Bachiashvili, 39, who once headed the Co-Investment Fund for Georgia’s de facto ruler, billionaire Bidzina Ivanishvili, accused officials of resorting to “banditry” and acting on Ivanishvili’s direct orders.

He told a Tbilisi court he was blindfolded for two days and then flown back “in complete violation of the law”, without access to his lawyers and family.

However, authorities say he was detained near a border crossing and Prime Minister Irakli Kobakhidze said he should be happy he was safely in Georgia.

Ivanishvili’s Georgian Dream party has been in power for 13 years, although the opposition considers the government and parliament “illegitimate”, citing widespread allegations of election fraud last October.

“Today I am Ivanishvili’s personal prisoner,” declared Bachiashvili in court on Thursday. He is due to return to court on 9 June.

Bachiashvili went on the run in early March, when he fled Georgia midway through a trial that later saw him sentenced in absentia to 11 years in prison for embezzlement, which he has vehemently denied.

He had been accused of misappropriating $42.7m from a Bitcoin investment deal, a case he said was politically motivated and led by Ivanishvili.

Although he did not say where he had been at the time of his alleged abduction on Saturday, a close friend said on condition of anonymity that Bachiashvili had been at a hotel in Abu Dhabi when three vehicles arrived, and he was seized.

“He gets extradited with no lawyer, no trial, absolutely nothing,” the friend told the BBC.

The BBC has approached the authorities in UAE for a response to the allegation.

The businessman also alleged that he had been forcibly returned on a Bombardier aircraft run by Airzena, the former name of privately owned Georgian Airways. In a statement, the airline said it was impossible for anyone to “board or depart from any international airport on any airline illegally”.

Whatever the circumstances surrounding his return to Georgia, the State Security Service announced he had been arrested on Monday after an anonymous tip-off near the Red Bridge border crossing with Azerbaijan.

That crossing has been shut by Azerbaijan since the 2020 coronavirus pandemic.

International lawyer Robert Amsterdam said this week that his client was at risk of “arbitrary detention, coercive interrogation, and abusive mistreatment”.

The head of Georgia’s state security service, Anri Okhanashvili, said Bachiashvili had been convicted of a crime and would serve his sentence, adding that not a single hair had fallen from his head, Interpressnews agency reported.

The prime minister said the businessman appeared to believe that his life was in danger. If that was the case then he should be happy he was back “in Georgia, in a safe place… in appropriate conditions”.

The allegations coincide with the departure of another close aide of Georgia’s most powerful man.

Long-serving interior minister Vahtang Gomelauri resigned on Wednesday without giving a reason, other than to spend more time with his family.

Gomelauri has in the past acted as a personal bodyguard for Bidzina Ivanishvili and he has been placed under economic sanctions from the US, the UK and several EU countries for his alleged role in violent suppression of anti-government protests.

Ivanishvili, whose estimated wealth is $4.9bn (£3.9bn), made his fortune in Russia in the 1990s in computing, metals and banking.

He established a political party in Georgia in 2011 and won elections the following year.

Bachiashvili told the Guardian he had served as Ivanishvili’s “right-hand man” for over a decade, managing the oligarch’s vast financial empire and acting as deputy chief executive of Georgia’s sovereign wealth fund.

He described playing a crucial role in recovering hundreds of millions of dollars stolen from Ivanishvili by a rogue Credit Suisse adviser, successfully leading complex legal battles across multiple jurisdictions.

However, according to Bachiashvili, their relationship soured after Russia’s invasion of Ukraine in 2022.

He added that Ivanishvili had operated like “a sultan and his servants” with prime ministers, judges and prosecutors, who had all made pilgrimages to his hilltop residence in the capital Tbilisi.

Bachiashvili’s case mirrors that of another fallen Georgian Dream ally, businessman Giorgi Chikvaidze, who was sentenced to nine years in prison on embezzlement charges in recent weeks after publicly turning against the ruling party and claiming to possess evidence of government ties to Russian intelligence.

“Everyone will be held accountable sooner or later,” Bachiashvili said in the dock on Thursday, promising to reveal “all the details” of what he called an international crime committed on his former boss’s direct orders.

Additional reporting by Paul Kirby and Nino Shonia.