An influential committee at the European Union's parliament voted unanimously on Tuesday to lift the protective immunity of two lawmakers being sought by Belgian authorities on suspected links to a major corruption scandal.

The European Parliament's legal affairs committee decided by 23 votes to zero, with no abstentions, to lift the parliamentary immunity of Belgian lawmaker Marc Tarabella and Italian Andrea Cozzolino, its chairman, Adrian Vazquez Lazara, announced on Twitter.

The move paves the way for the full house to vote on whether to remove their protections on Thursday so that the two men, who are members of the centre-left Socialists and Democrats (S&D) political group hardest hit by the scandal, can be questioned by Belgian prosecutors.

Hundreds of thousands of euros (dollars) were seized in raids across Brussels in December. Four people were charged with corruption, money laundering and membership in a criminal organisation for allegedly accepting bribes from Qatari and Moroccan officials to influence parliamentary proceedings.

They are S&D lawmaker Eva Kaili, who was an assembly vice president until the charges came to light; her partner and parliamentary assistant Francesco Giorgi; former S&D lawmaker Pier Antonio Panzeri, and the head of a charity group, Niccolo Figa-Talamanca.

Qatar and Morocco deny any involvement.

The request by prosecutors for parliament to lift the immunity of Tarabella and Cozzolino suggests that they too could be charged.

Both men deny wrongdoing and have said they are willing to talk to investigators.

A lawyer for Panzeri's wife and daughter, who were also being sought over suspected links to what's one of the EU's biggest-ever scandals, said Monday that they had been freed from house arrest after Belgian authorities abandoned their attempt to have the two transferred for questioning.

The two women have accepted to meet freely with investigators at an as-yet undetermined date.

The decision in Brussels came days after Panzeri agreed to become an informant in exchange for a lighter sentence, pledging to name names and detail financial arrangements with those involved.