A European Parliament vice president, Greek socialist MEP Eva Kaili, was charged with corruption and remanded in custody on Sunday after Belgian investigators found "bags of cash" in her home.
Belgian police are investigating allegations that figures working on behalf of Qatar, the Gulf monarchy and World Cup host, have paid European politicians huge bribes to influence the Brussels policy debate.
Kaili, who has spoken publicly in support of Qatar's recent labour reforms, was one of four suspects to have been charged and detained.
Two more have been released and the house of at least one more MEP has been searched by investigators.
The Belgian federal prosecutor's office did not identify the four by name, but a judicial source confirmed to AFP that Kaili was among those charged.
"Four individuals have been arrested by the Brussels investigating judge who is leading the investigation," the federal prosecutor's office said in a statement.
"They are charged with participation in a criminal organisation, money laundering and corruption. Two persons have been released by the investigating judge."
The arrests followed raids in Brussels which prosecutors said turned up €600,000 in cash. Police also seized computers and mobile phones.
'Bags of cash'
The second search of an MEP's house is understood to have involved a Belgian member, since the president of the parliament, Roberta Metsola, was invited to witness the raid.
The judicial source identified him as Marc Tarabella, a Belgian socialist and vice-chair of the parliamentary delegation "for relations with the Arab peninsula". He has not been charged.
Under the Belgian constitution the president of the European Parliament must attend if one of the country's MEPs is targeted by a search, Metsola's office confirmed.
"We can confirm that EP President Metsola has returned from Malta to Brussels on Saturday evening to be present at a house search of a Member of European Parliament," the spokesman said.
"The European Parliament and President Metsola stand firmly against corruption, are actively and fully cooperating with law enforcement and judicial authorities to assist the course of justice."
Kaili has been https://timesofmalta.com/articles/view/underfire-greek-mep-loses-vp-powers-qatar-graft-probe.1000825of her responsibilities as a vice president of the parliament, notably that of representing Metsola in the Middle East, but she is still an MEP and would normally enjoy immunity from criminal prosecution.
But there is an exception in cases where a suspect is caught red-handed in the act of committing an alleged crime and, according to the judicial source, Belgian police detained Kaili in possession of "bags of cash" and thus she was brought before the judge.
Among the six arrested on Friday, after at least 16 police raids of premises in Brussels, were the former MEP Pier-Antonio Panzeri and his fellow Italian Luca Visentini, the general secretary of the International Trade Union Confederation (ITUC).
'Strategic positions'
According to Belgian news reports, Kaili's father is also implicated, caught transporting cash "in a suitcase".
"It is suspected that third parties in political and/or strategic positions within the European Parliament were paid large sums of money or offered substantial gifts to influence parliament's decisions," the prosecutor's statement said, without pointing fingers at Qatar.
The scandal erupted during the 2022 football World Cup, an event Qatar had hoped would boost its reputation but which has been dogged by allegations of mistreatment of the migrant workers who built the host nation's new stadiums.
Kaili visited Qatar and its Labour Minister Ali bin Samikh al Marri just ahead of the World Cup and praised the Gulf nation as a "frontrunner in labour rights" a sentiment she has repeated on the floor of the parliament, to the consternation of some MEPs.
Questions of corruption are now expected to hang over this week's European Parliament plenary session in Strasbourg, where Kaili's party grouping the Socialists and Democrats will be under pressure from opponents on the right and left.
Metsola, herself a Maltese conservative, has called a meeting of the leaders of the parliament's political blocs on Monday to discuss the Belgian investigation, two parliamentary sources told AFP.
Some MEPs also now plan to oppose opening the debate on visa liberalisation for Qatari travellers, potentially derailing a key diplomatic goal of the gas-rich nation.