Prosecutors in France have placed the far-right leader Marine Le Pen under formal investigation as part of a probe into the alleged misuse of European Union funds to pay parliamentary assistants.
The 48 year old head of the National Front is being investigated for breach of trust and has denied any wrongdoing.
She says the case is politically motivated.
In a statement, her lawyer said she would launch an appeal.
Under French law, being put under formal investigation means there is “serious or consistent evidence” that points to probable involvement in a crime.
It is a step towards a trial, though investigations can be dropped without proceeding to court.
The case relates to an amount of about US$5.71 million.
The European Parliament believes the money went to National Front employees working for the party in France rather than those working for its lawmakers in Brussels.