BRUSSELS — The Belgian authorities arrested a European lawmaker on Friday in connection with a sprawling cash-for-favors investigation, the latest figure to be detained in a scandal that has ripped through the European Parliament since it came to light in December.
A spokesman for the Belgian prosecutor confirmed the arrest of the lawmaker, Marc Tarabella, as part of a yearslong inquiry into whether lawmakers accepted bribes from Qatar and Morocco, in exchange for supporting measures that would benefit the two countries politically and economically.
The arrest of Mr. Tarabella, of Belgium, hardly comes as a surprise: He and another lawmaker, Andrea Cozzolino of Italy, had their immunity revoked last week by the Parliament following a request from the Belgian authorities.
Mr. Tarabella is accused of supporting “certain positions within the European Parliament in favor of a third state” for the past two years, in exchange for up to 140,000 euros, about $153,000, according to a report adopted by lawmakers, who had access to confidential documents from the Belgian judiciary.
Mr. Cozzolino, who has not been taken into custody, is suspected of “accepting money in exchange for protecting the interests of foreign powers,” in particular by “preventing the adoption of parliamentary resolutions which could harm” their interests.
Earlier on Friday, the Belgian police searched what they said was Mr. Tarabella’s bank vault in the Belgian city of Liège, about 55 miles east of Brussels, as well as his offices in the nearby city of Anthisnes, the prosecutor said in a statement.
Following a hearing, which is expected later on Friday, a judge will decide whether and how to charge Mr. Tarabella. The Belgian lawmaker has repeatedly claimed his innocence, and said he voted in favor of revoking his immunity.
“I have been asking for the lifting of this immunity since the very first days of this case, in order to be able to answer the questions of the investigators and help the justice to shed light on this file,” Mr. Tarabella said.
Three people linked to the European Parliament were arrested in the snowballing investigation late last year: Eva Kaili of Greece, Parliament’s former vice-president; Francesco Giorgi, her partner and a parliamentary aide; and Pier Antonio Panzeri, a former lawmaker.
They are currently in jail in Brussels and have been charged with forming a criminal organization, corruption and money laundering. A fourth person, Niccolò Figà-Talamanca, the head of a Brussels-based human rights organization, has been charged and released, but he must wear an electronic monitoring device.
Ms. Kaili has denied any wrongdoing through her lawyer, as has Mr. Panzeri. Mr. Giorgi has not commented.
A major breakthrough in the case came last month, when Mr. Panzeri, whose wife and daughter have been arrested in Italy and are awaiting extradition, cut a deal with the prosecutor to provide detailed information in exchange for a lighter sentence. His wife and daughter have also denied any wrongdoing.
Mr. Panzeri has been cast by the Belgian authorities as the central figure of a corruption network and pledged to reveal the identity of others involved.
The corruption scandal could be the biggest in the history of the Parliament, the only European Union institution in which the positions are directly elected.
The assembly is the least powerful of all the bloc’s institutions when it comes to foreign policy, but its resolutions can influence the reputations of countries, especially in the realm of human rights. The arrests late last year, the first in the case, coincided with the men’s soccer World Cup, which was hosted by Qatar as part of a long-running effort to improve the country’s international standing.