Paris - French prosecutors said they have put a Lebanese banker under formal investigation, the latest move in a cross-border probe looking into whether Lebanon’s central bank governor Riad Salameh, embezzled vast sums of public funds.

The Lebanese banker, Marwan Kheireddine, who is the chairman of Lebanon's AM Bank, is suspected of participation in a criminal association and aggravated money laundering, a spokesperson at the Paris office of the National Financial Prosecutors said on Friday.

Kheireddine, who was in France on March 24 when prosecutors notified him of the preliminary charges, was not kept in custody, the spokesperson said, but he was told not to leave the country and his passport was confiscated.

Kheireddine did not respond to phone calls and text messages. A lawyer who, Reuters was told represents him, said he could not confirm being Kheireddine's counsel.

Salameh, who has been at the helm of the central bank for three decades, is being investigated in Lebanon, in France and in at least four other European countries over accusations of stealing hundreds of millions of dollars and laundering some of the proceeds abroad.

Salameh has denied the accusations, saying he is being made a scapegoat for Lebanon's financial crisis that erupted in 2019.

According to people familiar with the French and Lebanese probes, Kheireddine is suspected of having allowed Salameh to process irregular fund transfers through AM Bank.

A lawyer for Salameh, Pierre-Olivier Sur, declined to comment on the allegations Kheireddine colluded with the governor. The Lebanese bank did not respond to a message seeking comment.

In January, Kheireddine was questioned by visiting European prosecutors in Beirut, who asked him about accounts at AM Bank containing large sums of money belonging to Salameh, according to people familiar with the interrogation.

Bank statements seen by Reuters show how the Salameh accounts at AM Bank ballooned from $15 million in 1993 to more than $150 million by 2019.

Lebanese prosecutors suspect the accounts, from which regular cash withdrawals were made, were used to conceal money laundering activity, a Lebanese judicial source said on Saturday.

Through lawyers, Salameh has denied using his AM Bank accounts to launder money, saying interests he capitalized on deposits explain why his savings rose.

Kheireddine served as a Lebanese minister of state between 2011 and 2013 and ran unsuccessfully for parliament in 2022 on a list backed by the powerful Iran-backed political party and armed group Hezbollah.

French prosecutors, who have not formally named Salameh a suspect, have summoned him for a hearing in Paris on May 16, according to Salameh's lawyer, Sur.

Sur said late on Friday it was not clear whether his client would be able to come to the hearing because his travels are restricted as part of Lebanese investigations.

Sur told Reuters he may challenge the hearing itself on procedural grounds.

According to the lawyer, French prosecutors have summoned his client with a view of naming him a formal suspect. Yet, in March, they came to Beirut, and questioned him as a "simple witness," he said.

If French prosecutors suspected Salameh of wrongdoing, they could not hear him as a witness, Sur said. The fact they did creates an "insurmountable gap" the lawyer said.

(Reporting by Layli Foroudi in Paris, David Gauthier-Villars in Istanbul and Timour Azhari in Beirut; Writing by David Gauthier-Villars; Editing by Tomasz Janowski)