Pictured: Suitcases stuffed with cash seized by police investigating Qatar bribery of European politicians

Police in Belgium have released pictures showing suitcases full of money allegedly used to bribe politicians in one of the biggest corruption scandals to ever hit the European Parliament (EP).

The Belgian Federal Police raided numerous buildings in Brussels, including parliament offices and 19 homes, discovering around 1.5m euros (£1.29m), some of it stashed in a suitcase in a hotel room.

Belgian prosecutors have now charged Greek MEP Eva Kaili, as well as three Italians, with taking part in a criminal organisation, money laundering and corruption.

Sources told the Reuters news agency that former EU lawmaker Pier Antonio Panzeri, Kaili's partner Francesco Giorgi, who is a parliamentary assistant, and Niccolo Figa-Talamanca, secretary-general of a human rights campaign group, are the three others who have been charged.

A source close to the investigation said that that they were believed to have pocketed money from Qatar – the current host of the World Cup – in an attempt to buy influence in Brussels.

However, the energy-rich Gulf state has denied any wrongdoing.

Qatar drew fierce criticism of its human rights record in the run-up to the World Cup, including its treatment of migrant workers and stance on same-sex relationships.

Watch: MEP Eva Kaili stripped of vice president role as Qatar corruption probe widens

In a speech in the EP last month – at the start of the World Cup – Kaili hit out out at Qatar's detractors and hailed the country as "a frontrunner in labour rights”.

The EP has now removed Kaili, who has also denied any wrongdoing, as a vice president of the assembly.

Kaili's lawyer, Michalis Dimitrakopoulos, said that his client was innocent, telling Open TV: "She has nothing to do with financing from Qatar, nothing, explicitly and unequivocally.”

Nevertheless, European lawmakers have acted rapidly to isolate her, worrying that the Belgian investigation will badly dent the assembly's efforts to present itself as a sound moral compass.

EP president Roberta Metsola said: "There will be no sweeping under the carpet. Our internal investigation will look at what has happened and how our systems can be made more watertight.”

Countries and politicians on the nationalist right, who have faced criticism from the assembly, said the EP had lost the moral high ground.

"From now on the European Parliament will not be able to speak about corruption in a credible manner," Hungarian foreign minister Peter Szijjarto wrote on Facebook.

Jordan Bardella, a French MEP and president of the far-right Rassemblement National, said the scandal showed what he called the "mockery" of an EU "which has set itself up as a model of virtue, a giver of lessons".