Francesco Giorgi, the partner of disgraced former European Parliament vice president Eva Kaili, is being conditionally released and placed under house arrest, the public prosecutor's office in Brussels said on Friday.
Kaili, Giorgi and two others were taken into custody in December in relation to a huge corruption scandal linked to Qatar that has engulfed the EU legislature.
Giorgi will have to wear an electronic tag on his ankle, the prosecution said, adding that it would not appeal against the decision taken on Thursday evening.
Belgian prosecutors raided various premises in December while investigating corruption, money laundering and influence peddling. Qatari officials are suspected of seeking influence on the bloc's political decision-taking.
Kaili, Giorgi and the two others held in custody since December 11 - including the alleged leader of the group Antonio Panzeri - are accused of participating in a criminal conspiracy, money laundering and corruption.
In January, Panzeri signed an agreement with the public prosecutor's office promising his full cooperation in the investigation.
Giorgi last worked for Italian EU lawmaker Andrea Cozzolino, who was also arrested for possible involvement in the scandal.
