A coordinated police swoop across Europe on Thursday netted 22 arrests and saw villas and luxury cars seized in Italy, in a probe into an alleged 600-million-euro ($650 million) fraud of EU Covid funds, officials said.

Dozens of raids took place in Italy, Austria, Romania and Slovakia as authorities moved in against a suspected criminal network that carried out the alleged fraud between 2021 and 2023, the European Public Prosecutor's Office (EPPO) said.

The focus of the operation was in Italy, where the Venice office of Italy's financial police unit, the Guardia di Finanza, seized assets worth over 600 million euros on the authority of a pre-trial judge.

The assets include "stately apartments and villas, significant sums in cryptocurrencies, high-end watches (Rolex), jewellery (Cartier), gold, and luxury cars (including Lamborghini Urus, Porsche Panamera and Audi Q8)," the Venice police unit said in a statement.

It said that more than 150 financial police officers conducted raids in cities and towns across the country, "assisted by cash-detection dogs".

The EPPO said that, of the 22 arrested suspects, eight were put in detention pending trial and the other 14 were under house arrest, with one, an accountant, banned from practising.

The European Union's Recovery and Resilience Facility, established to help the bloc bounce back from the economic blow dealt by the Covid pandemic, is worth more than 800 billion euros, financed in large part through common EU borrowing.

That model, particularly the joint borrowing, has been touted by some EU countries as one to replicate as the European Union steps up its defence industry and cooperation in response to the threat from Russia, and to support Ukraine.

Italy has been the largest beneficiary of the fund, with a total endowment of 194.4 billion euros through a combination of grants and loans.