PARIS (Reuters) – French authorities are seeking to recover 2.5 billion euros ($2.75 billion) in back taxes from several banks over their alleged roles in a scheme used to avoid taxes linked to dividend payments, Budget Minister Gabriel Attal said.

Attal gave the figure in a recorded public Senate hearing on May 2, the first time the government has quantified the potential losses to state finances from the so-called cum-cum trades designed to dodge such taxes.

Attal did not name the banks issued with the demands, and said work was ongoing to determine the amount of lost tax revenue.

Newspaper Le Monde first reported Attal’s comments on Monday, adding the 2.5 billion euro figure regarded alleged fiscal fraud from 2017 to 2019.

Attal’s office did not immediately respond to a request for comment on Tuesday. A spokesman for the financial prosecutors’ office declined to comment.

French tax authorities in March searched the Paris offices of five banks, including Societe Generale, BNP Paribas and HSBC on suspicion of fiscal fraud in the case.

The searches also targeted Exane, which is part of BNP Paribas, and Natixis, the investment bank arm of French banking group BPCE. Similar investigations have been conducted in Germany and other European countries.

The banks have declined to comment.

The French banks allegedly helped foreign clients by temporarily taking the shares they held in French companies around dividend days to avoid tax being levied on them, prosecutors said in March.

Days after the searches, the French banking federation said it had brought a case with the country’s highest administrative court to demand more clarity from the government on applicable dividend tax rules.

(Reporting by Silvia Aloisi; Editing by Richard Chang)

A BNP Paribas logo is seen outside a bank office in Paris, France, August 6, 2018. REUTERS/Regis Duvignau