The Paris prosecutor's office has launched a preliminary investigation to see if BNP Paribas provided misleading information about investments in a fund buying Madoff-related products, a newspaper said on Saturday.

Without naming its sources, the Journal du Dimanche newspaper said the prosecutor was acting on a complaint by lawyer Olivier Metzner on behalf of clients who had lost money investing with Bernard Madoff.

Madoff, 70, pleaded guilty on March 12 to running a worldwide fraud that prosecutors said went back at least 20 years, drawing in as much as $65 billion from big and small investors and charities.

"The lawyer suspects the bank of having attracted people to the Luxalpha fund by curiously-worded subscription forms," the newspaper said. BNP created the Luxalpha fund before handing the management to Swiss bank UBS in 2004, the paper said.

BNP (BNPP.PA) denied ever having advised clients to buy Madoff products and said it would in turn file a complaint for slander.