Belgian prosecutors investigating allegations that Qatar has sought to influence EU policy by bribing European parliament officials have charged four people with money laundering, corruption and participating in a criminal organisation. The charges, which were announced on Sunday, came two days after police arrested four people and seized computers, mobile phones and €600,000 (£515,000) in cash during searches at 16 properties across Brussels. According to Belgium’s federal prosecutor, officers examining one of the biggest alleged corruption cases in the parliament’s recent history believe a Gulf country – identified by Belgian media as Qatar – has used bribes and gifts to try to influence decisions at the legislature. Although the prosecutor’s office did not identify the four by name, a judicial source told Agence France-Presse that they include Eva Kaili, an MEP for the social democratic Greek Pasok party who serves as one of the parliament’s 14 vice-presidents. The home of a second MEP was searched on Saturday evening, the prosecutor’s office said. “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 office said in a statement. “Four individuals have been arrested by the Brussels investigating judge who’s leading the investigation. They are charged with participation in a criminal organisation, money laundering and corruption. Two persons have been released by the investigating judge.” A Qatari official denied accusations of possible misconduct and said the country worked in full compliance with international laws. He added: “Any association of the Qatari government with the reported claims is baseless and gravely misinformed.” Kaili, a former television presenter, met Qatar’s labour minister, Ali bin Samikh Al Marri, shortly before the World Cup began last month. In a video statement posted on Twitter by the state-run Qatar News Agency, she said: “I believe the World Cup for Arabs has been a great tool for … political transformation and reforms.” In a subsequent speech at the European parliament she said: “Today, the World Cup in Qatar is proof … of how sports diplomacy can achieve a historical [sic] transformation of a country.” While Kaili has been stripped of her powers as a vice-president of the parliament, which sits in Brussels and in Strasbourg, she is still an MEP and would normally enjoy immunity from criminal prosecution. There is, however, an exception in cases where a suspect is caught red-handed committing a crime. According to the judicial source, Belgian police detained Kaili in possession of “bags of cash”, meaning she was brought before the judge for having been caught “in flagrante delicto”, or in the act of committing an offence. Greek media reported that Kaili’s Italian partner, Francesco Giorgi, who works as a consultant at the European parliament, had also been detained. The scandal sent ripples through Greece where there was mounting concern the corruption probe could dent the country’s image. Pasok’s leader, Nikos Androulakis, wasted no time expelling the EU lawmaker from his centre-left party, telling a party conference on Sunday that he would not accept “even a grain of suspicion in matters of transparency”. An MEP himself, Androulakis took the decision to fire the former news presenter within hours of the revelations emerging on Friday. Soon after the European social democrats group also announced it was suspending the 44-year-old. Kaili’s ties with her own party – Greece’s third-largest political force – had become increasingly strained, prompting Androulakis to describe her as a “Trojan horse” of the governing New Democracy party. Despite representing an opposition group in the European parliament, Kaili had been publicly backed by the Greek prime minister, Kyriakos Mitsotakis, in her quest to become a vice-president. “It is not only embarrassing for Pasok but Mitsotakis personally because he lobbied so hard for her to get the post,” said one MEP. “Kaili isn’t the only Greek [lawmaker] to make flattering remarks about Qatar.” In April, the EU Commission’s vice-president, Margaritis Schinas, a New Democracy politician, tweeted that “short-stay visa-free travel” to member states for Qatari and Kuwaiti citizens was being proposed as a result of “the remarkable success of both governments in achieving far-reaching reforms”. Although Schinas’ tweet was republished by the Greek media at the weekend, outlets noted there was no suggestion of impropriety on the part of the politician. On Saturday, the president of the European parliament, Roberta Metsola, said the institution “stands firmly against corruption” and would do everything it could to “assist the course of justice”. The socialists and democrats group in the European parliament said it was appalled by the corruption allegations and called for urgent action. “Given the seriousness of the allegations, until the competent authorities provide relevant information and clarification, we are requesting the suspension of work on any files and plenary votes regarding the Gulf states, particularly visa liberalisation and planned visits,” the group said in a statement. Daniel Freund, an MEP and the co-chair of the European parliament’s anti-corruption intergroup, said the allegations, if confirmed, would constitute one of the most serious corruption scandals in Brussels in recent decades. “The current incident shows how aggressively third countries try to exert influence in the EU,” he said. “Those who do so by illegal means, or even by bribery, must be punished.” Part of the problem, he added, was that third countries had been exempted from Brussels’s “relatively good” lobbying rules. “Money must not buy influence in the EU,” Freund said. “The suspicion alone is intolerable. The accusations must be fully investigated. There is a threat of a loss of confidence in the European parliament, although it is actually one of the most transparent parliaments in Europe.” Alberto Alemanno, a professor of EU law at HEC Paris, described the allegations as “the most shocking integrity scandal in the history of the EU” and said it underlined the need for reform.