French police raided parliament in an investigation into Francois Fillon and his wife Penelope
The probe was carried out on Tuesday, just a day after the right wing Republican candidate and his wife were interrogated by police.
Mr Fillon, 62, and his Welsh-born wife Penelope face a series of questions about whether or not she did a "fake" job that she was paid £430,000 (€500,000) of taxpayers money to do for more than eight years.
It was not immediately known if Mr Fillon’s office was searched during the raid, but police were looking for employment contracts.
The highly unusual police raid of the lower house of parliament had to be sanctioned by the speaker of the house in a move that has split the political spectrum.
Police had a good look around the lower house, but Mr Fillon’s townhouse was not searched.
French media has dubbed the high-profile investigation the 'Penelopegate scandal', and it has taken centre stage in the presidential election race.
Francis Fillon now ranks behind the National Front’s Marie Le Pen.
Despite the probe, questions still remain about the legitimacy of his wife's job as parliamentary assistant.
Investigators want to work out whether or not she actually carried out her role – as not doing so would be a breach of the rules.
While it is not illegal for French ministers to employ their spouses, the spouse must perform the role.
Mr Fillon and his Welsh-born wife Penelope are facing a probe into misusing cash
The probe came about after accusations surfaced in a newspaper that she did not do the job.
Last week, Le Canard Enchain newspaper accused Penelope of being paid the cash despite claiming she did not "have a role" in her husband's office both last year and in 2008.
But the presidential candidate hit back, saying that the investigation is “part of a smear campaign” as his wife’s work was “real and legal”.
Both Mr Fillon and his wife were questioned for five hours each by police on Monday.
The probe is very embarrassing for the pair as both are familiar faces in France.
Mr Fillon ran his campaign on being a clean politician but has now said that he wants the probe to happen quickly.
He also pledged to withdraw from the presidential race if he is put under a formal investigation.
The French financial prosecutor has launched a preliminary inquiry which could lead to a formal investigation.
Fillon, who represents the centre-right party Les Republicains' had been a frontrunner in the presidential debate until the controversy dented his standing in the polls.
He now ranks behind the Front National's Marie Le Pen.
Candidates for the 2017 French Presidential Election
Mon, January 30, 2017
Who will be the next President of France?
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Francois Fillon takes a hard line on immigration
Francois Fillon was elected as presidential candidate by a landslide
Presidential candidate Francois Fillon DEFENDS wife Penelope