Along the banks of the Danube, news that the Viktor Orbán era had come to an end set off an hours-long party. The joy echoed across Hungary as people traded hugs and high-fives. For some, however, the landslide loss set off a frantic scramble.

Private jets allegedly laden with the spoils of those whose wealth swelled during Orbán’s 16 years in power have steadily been taking off from Vienna, while other individuals are racing to invest their assets abroad, sources have told the Guardian. Meanwhile, high-level figures close to Orbán have been looking into US visa options, hoping to find work at Maga-linked institutions.

It is a glimpse of the upheaval that has gripped Hungary as it prepares to turn the page on Orbán’s rule. Since he took power in 2010, a small circle of associates aligned with the leader and his Fidesz party have amassed vast fortunes, party due to their expanding control over the country’s economy and EU-funded contracts for public infrastructure.

Since the election, the Guardian has learned of three members of this inner circle who have begun moving their assets abroad. The wealth is being moved to countries in the Middle East – Saudi Arabia, Oman and the UAE – while others have their sights set on Australia and Singapore, two Fidesz sources said.

Péter Magyar, whose opposition Tisza party won a landslide victory this month, has sounded the alarm, accusing those connected to Fidesz of racing to shield their wealth from accountability before his government takes power in early May.

“Orbán-linked oligarchs are transferring tens of billions of forints to the United Arab Emirates, the United States, Uruguay and other distant countries,” Magyar alleged on social media on Saturday. He called on the chief prosecutor, the police chief and the head of the tax office to “detain the criminals” and “not to allow them to flee” to countries where extradition would be unlikely.

Magyar said those expected to leave the country included the family of Lőrinc Mészáros, one of Orbán’s closest friends, whose trajectory from gas fitter to Hungary’s richest man was fuelled in part by public procurement contracts. Mészáros’s company did not immediately respond to a request for comment.

“I have also been informed that several oligarch families have already left the country,” Magyar added. “According to reports, several influential oligarch families have already withdrawn their children from school and are arranging trusted security personnel for their departure.”

The race to move wealth abroad was first reported by independent journalists in Hungary, including the investigative outlet Vsquare, which said key figures connected to Orbán aimed to safeguard their assets before Magyar’s government could potentially freeze, seize or nationalise them, and the news site 444.hu, which in March claimed key figures were already transferring assets to Dubai.

Their efforts could be stymied by the many bureaucrats and law enforcement officials who have partial knowledge of all that took place during Orbán’s time in power, Vsquare noted, “setting the stage for what could be a years-long efforts to recover allegedly stolen public wealth and arrest those who committed financial crimes”.

Since the election, Magyar has repeatedly said his government will work to crack down on the corruption and cronyism that, in his view, characterised Fidesz’s years in power. “Our country has no time to waste. Hungary is in trouble in every respect. It has been plundered, looted, betrayed, indebted and ruined,” Magyar told reporters the day after the election. “We became the most impoverished and the most corrupt country in the EU.”

The incoming leader has repeatedly alleged that potentially incriminating documents are being destroyed during Orbán’s last weeks in power. “We are receiving increasing reports of large-scale document destruction from various ministries, affiliated institutions, and companies close to Fidesz,” he wrote on social media earlier this month.

The outgoing foreign minister, Péter Szijjártó, whose ministry was among those accused of shredding confidential documents, described the accusations as “nonsense” and “outrageous” in a statement to the Hungarian online news outlet Telex. The ministry said it had “only discarded the previously printed, redundant paper versions of documents that had been stored electronically”.

The foreign ministry and the office of Orbán, who has long rejected allegations of corruption and wrongdoing, did not respond to requests for comment from the Guardian.

The election result has sparked questions as to what comes next for Orbán, the strongman leader whose efforts to turn Hungary into, in his words, a “petri dish for illiberalism” have inspired Donald Trump’s administration and the global far right.

On Saturday, Orbán said on social media that he would not take his seat in parliament but that he aimed to stay on as Fidesz’s leader in order to lead a process of “renewal”.

The EU’s longest-serving leader is expected to head to the United States around the same time as the Fifa World Cup kicks off and will probably spend several weeks there, a Fidesz-linked source told the Guardian. The source said the trip had been planned long before the 12 April election.

Where Orbán will travel to exactly is unknown, though his eldest daughter and son-in-law moved to New York last summer.

The son-in-law, István Tiborcz, burst into public view in 2018 when the EU’s anti-fraud office, Olaf, said a two-year investigation into contracts to supply Hungarian towns with EU-funded street lamps had found “not only serious irregularities in most of the projects, but also a conflict of interest”. While Olaf does not publish its reports or reveal who is named in them, the Guardian understands that the irregularities related to contracts signed when Tiborcz was an owner of the company concerned.

A representative for Tiborcz referred the Guardian to a July interview in which Tiborcz described the EU inquiry as politically motivated. The matter was also investigated by Hungarian prosecutors, led by an Orbán loyalist, who found no breach of law.

Other high-level figures connected to Fidesz are applying for US work visas, hoping to use their expertise in institutions linked to the Republican party, a US government source in Washington and a source inside Fidesz said.

“The connection is already there,” said the US source, adding that years of lobbying by Orbán and Fidesz had allowed Hungarian officials to cultivate an extensive network within the Maga movement. These connections were laid bare in the lead-up to the election when the US vice-president, JD Vance, turned up in Budapest to bolster Orbán’s lagging campaign.

Days after the election, one of Hungary’s most prominent investigative journalists, Szabolcs Panyi, said sources had told him the US had long been seen as a plan B for many who were connected to Orbán, despite the questions that continue to swirl over Orbán and his government’s connections to Moscow.

“As long as the Trump administration is in power, even the United States could become a safe haven for the top echelons of the Orbán regime,” Panyi said.