Russian oligarch Vitaly Malkin is suing Credit Suisse for the loss of $515 million he claims was the fault of a former adviser at the Swiss banking giant, Sonntagszeitung daily reported Sunday.

Malkin, a resident of Monaco and an ex-business partner of former Georgian Prime Minister Bidzina Ivanishvili, has hired the American firm Quinn Emanuel to sue Credit Suisse in the case concerning Patrice Lescaudron, the newspaper reported.

Lescaudron was a former private banker at Credit Suisse in Geneva but was sacked in 2015. A Swiss court later sentenced him to five years in prison in 2018 on charges of fraud and forgery, Swiss media reported. Lescaudron died by suicide in 2020.

The bank told AFP it "rejects all the allegations".

"Credit Suisse was recognised as the aggrieved party by all criminal authorities seized with this matter," it said in a statement.

The latest case comes after a Bermuda judge ruled in March that Ivanishvili suffered a loss of $553 million because of failures by a Credit Suisse affiliate in Bermuda.

The ruling said the Credit Suisse affiliate did not prevent Lescaudron's fraud because "it was prioritising the revenues Mr Lescaudron generated for Credit Suisse over the interests of its clients".

Credit Suisse said it would appeal against the ruling.

The bank insists Lescaudron acted alone.

"All investigations into this matter conducted by the bank, FINMA (The Swiss Financial Market Supervisory Authority) and the criminal authorities since 2015 have shown that the former relationship manager was not supported by any other employee of the Credit Suisse in his criminal activities," it said, referring to all the claims against Lescaudron.

Swiss business news agency AWP reported this week that prosecutors have launched separate legal proceedings against the bank after Lescaudron's death.