Athens froze Monday the assets of European Parliament Vice President Eva Kaili after the Greek MEP was arrested on corruption charges over her alleged involvement in a graft scandal linked to a Gulf state.

The measure, which also applies to her relatives, includes "bank accounts, safes, companies and other financial assets," said the Greek anti-money laundering authority president Haralambos Vourliotis.

Greek banks and state services have already been informed of the decision, the authority said.

The 44-year-old former television presenter was charged with corruption on Sunday in Brussels.

Belgian police were investigating allegations that figures working on behalf of a Gulf state may have paid European politicians to influence the Brussels policy debate.

Kaili has spoken publicly in support of Qatar's recent labor reforms. She was one of four suspects to have been charged and detained after Belgian investigators found "bags of cash" in her home.

She would normally benefit from immunity from criminal prosecution, but there is an exception in cases where a suspect is caught red-handed in the act of committing an alleged crime.

Kaili has been stripped of her responsibilities as a vice president of the parliament, notably that of representing parliament president Roberta Metsola in the Middle East. But she remains an MEP.

EU foreign policy chief Josep Borrell on Monday said the investigation into alleged corruption was "very worrisome."

"Certainly the news is very worrisome," Borrell told reporters as he arrived at a meeting of EU foreign ministers. "We are facing some events, some facts that certainly worries me as a former president of the European Parliament, also."

The Greek socialist PASOK party said in a statement that it was expelling Kaili from its ranks. Her office did not answer telephone calls or respond to an email requesting comment.

The European Parliament was due to vote this week on a proposal to extend visa-free travel to the EU for Kuwait, Qatar, Oman and Ecuador. Some lawmakers have suggested the debate and vote should be postponed.