Since 2012, Fillon has received clothes worth nearly €48,500 ($51,800) by Arnys, Parisian tailor to the rich and famous, the weekly Journal du Dimanche (JDD) reported.
Of that sum, €35,500 was paid in cash, the paper said, adding that a young woman generally delivered the money to the chic Left Bank shop that has catered to the likes of Andy Warhol and Yves Saint Laurent.
An order for two suits completed in early February however was paid for by cheque, signed by a “generous friend” who asked to remain anonymous, the paper said.
“I paid at the request of Francois Fillon,” JDD quoted the cheque's signatory as saying, adding: “by the way, without receiving the slightest thanks since then.”
Fillon's spokesman Luc Chatel reacted angrily to the report, denouncing what he called a “gutter campaign” against the candidate.
“How far are they going to take this?” he asked with the first round of the presidential election just six weeks away and Fillon, 63, facing charges over the fake jobs scandal on Wednesday.
“Are they going to check whether his grandmother had a Russian loan, and if he declared it in his assets statement?” Chatel fumed on French radio.
A member of Fillon's entourage confirmed that one of his friends gifted him two Arnys suits in February, adding that there was “nothing reprehensible” about it.
“We wonder how far these malicious intrusions into his private life will go,” the source said.
He dismissed as “outlandish” the paper's assertion that cash payments were made on Fillon's behalf for other Arnys clothing.
“No serious tailor's shop would accept cash payments in such amounts,” he said.
Poll numbers hit
For its part the store angrily refused to answer queries from the JDD.
Fillon's campaign went into a tailspin in January when the satirical and investigative weekly Le Canard Enchaine revealed that he had arranged for fake parliamentary jobs for his wife worth hundreds of thousands of euros.
Once the frontrunner to become France's next president in May, Fillon has had to battle to stay in the race because of the revelations.
His poll numbers have suffered and he is now in third place behind centrist Emmanuel Macron and far-right leader Marine Le Pen.
Last week the Canard Enchaine came out with a new revelation, that Fillon had received an interest-free, undeclared loan of €50,000 from a billionaire friend.
The candidate “did not deem it necessary” to report the loan to a state transparency watchdog, the paper said.