BRUSSELS >> A former lawmaker at the heart of the European Parliament corruption scandal has reached an agreement with Belgian authorities to trade detailed information in return for a lighter sentence, the latest twist in the blockbuster case, the prosecutor’s office said Tuesday.

The lawmaker, Pier Antonio Panzeri, an Italian who sat in the Parliament from 2004 to 2019, is one of four people who have been in the custody of the Belgian police since their arrests last month in the biggest corruption scandal ever to hit the EU institution.

Panzeri, 67, and the other defendants stand accused of accepting cash from Qatar and Morocco to influence lawmakers to act favorably toward those countries. Qatar and Morocco have denied any wrongdoing.

Panzeri had been cast as the central character in the case by Belgian authorities, who present him as a criminally entrepreneurial former politician who used his connections and influence to advance dodgy deals.

Panzeri and the other defendants — who include a ranking member of the Parliament and a former aide to Panzeri — have been charged with forming a criminal organization, corruption and money laundering.

On Dec. 9 police raided Panzeri’s home and, they say, found a bag with 700,000 euros (about $750,000) in cash. That same day they arrested Eva Kaili, a parliamentary vice president, and her partner, Francesco Giorgi, who had once served as an aide to Panzeri and was working as an aide to another lawmaker at the time of his arrest.

In all, the authorities say they recovered 1.5 million euros in raids at the suspects’ homes and elsewhere.