French investigators have searched the Paris home of conservative presidential candidate Francois Fillon, reports say.
The raid on Thursday morning was part of an investigation into an allegedly fake job given to his wife.
Mr Fillon has vowed to keep his candidacy going despite growing pressure. Several supporters have resigned from his campaign.
He was once seen as the favourite to win the election but his poll rating has dropped.
The allegations circling around the Fillon family focus mainly on his Welsh-born wife Penelope, who is also reported to be facing an investigation.
The Le Canard Enchaine newspaper alleges she was paid €831,400 (£710,000; $900,000) over several years for working as a parliamentary assistant for Mr Fillon and his successor, but had no parliamentary pass – raising questions over whether she did the work she was paid for.
He denies any wrongdoing.
On Wednesday, he complained he was the victim of a “political assassination”, and attacked the judiciary for supposedly treating him unfairly.
The raid is seen by many people on the right as another sign of how the scandal has totally eclipsed Mr Fillon’s ability to run a campaign, the BBC’s Hugh Schofield in Paris reports.
For the first time since the affair broke out a month ago, there is open dissension in the ranks about his candidacy, our correspondent adds.
Mr Fillon says he has been summoned to appear before a judge on 15 March, just two days before the deadline for candidates to submit their final applications.
The first round of the election takes place on 23 April, followed by a run-off on 7 May.
