Illustration shows Euro banknotes and torn EU flag
A torn European Union flag is placed on Euro banknotes, September 7, 2022 in this picture illustration. Reuters

Belgium launched an investigation on Friday into possible corruption involving an unidentified Gulf state and at least one member of the European Parliament, the federal prosecutor said.

The prosecutor said 16 houses were searched in Brussels on Friday as part of a major investigation into alleged offences of criminal organisation, corruption and money laundering.

A spokesperson for the prosecutor said a member of the European Parliament had been held for questioning and was still in custody on Friday evening, without giving further details.

In an emailed statement, the prosecutor said investigators from the Federal Judicial Police had for months suspected a Gulf country of trying to influence the economic and political decisions of the European Parliament by "paying large sums of money or offering large gifts to third parties with a significant political and/or strategic position within the European Parliament".

A spokesperson for the parliament told Reuters it would not comment on a continuing judicial investigation, but would work together with local authorities if needed.

About 600,000 euros ($633,300) in cash was recovered and computer equipment and mobile phones were seized, the prosecutor said.

Four people, born in 1955, 1969, 1971 and 1987, were arrested for questioning, including a former EU lawmaker and assistants working in the parliament, and may be brought before the investigating judge, the prosecutor said.

($1 = 0.9474 euros)