The Paris offices of UBS have been searched as part of an investigation into allegedly aiding tax evasion, suggesting that a probe of the firm’s French wealth management activities is gaining momentum.

The move was part of a broader enquiry which saw the bank's offices in Bordeaux, Strasbourg and Lyon searched in July.

"The examining magistrate Guillaume Daieff indeed went to the Parisian headquarters of UBS France as part of his enquiry," the bank was quoted by Reuters as saying in a statement, adding that the bank was cooperating with the probe.

Agence France Presse, citing a source, reported that two people had already been placed under investigation as part of the probe. The search was carried out by about 10 investigators from France's National Customs Service, the publication said.

Prosecutors in April opened a preliminary investigation into the French activities of UBS, suspected of marketing financial placements aimed at allowing subscribers to hide funds from tax inspectors, reports said.

"UBS (France) S.A. is fully cooperating with the French authorities," a spokesperson for UBS told WealthBriefing.