The European Parliament was on Monday getting to grips with allegations of huge cash bribes given to MEPs by figures working on behalf of World Cup host Qatar.
The scandal was exposed by Belgian prosecutors investigating claims that Qatar had sought to influence EU decision-making by bribing European parliament officials.
Four people were arrested and charged with “participation in a criminal organisation, money laundering and corruption”.
One of the assembly's vice presidents, Greek socialist Eva Kaili, has been charged with corruption by Belgian prosecutors and her assets have been frozen by her homeland.
MEP suspended
Kaili was suspended from her duties by the European Parliament and expelled by Greece's socialist PASOK party.
Three of Kaili's associates have also been charged after bags of cash were found in her home shortly after she returned from an official visit to Qatar.
It’s understood the home of Belgian socialist MEP Marc Tarabella has also been searched.
Vice-chair of the parliamentary delegation "for relations with the Arab peninsula”, Tarabella has not charged.
The arrests were made after prosecutors searched 16 houses and seized 600,000 euros in Brussels on Friday.
'Worrisome' news
“Certainly the news is very worrisome,” said European Union foreign policy chief Josep Borrell of the probe, which has triggered calls for more oversight of European policymaking.
EU foreign ministers in Brussels to discuss sanctions against Iran and Russia on Monday said the scandal threatened the credibility of European institutions.
"The allegations against the vice president of the European Parliament are of utmost concern, very serious," European Commission President Ursula von der Leyen said.
"It is a question of confidence of people into our institutions, and this confidence and trust into our institutions needs higher standards."