Russian cellist Sergey Roldugin allegedly moved millions of Swiss francs through Swiss bank accounts without proper checks, Swiss prosecutors said on Wednesday.

Roldugin is a close friend of Russian President Vladimir Putin and the godfather of the leader's eldest daughter.

Prosecutors made the comments in a trial of four bankers accused of helping Roldugin.

What do we know about the trial?

The four bankers appeared at Zurich District Court and denied charges of lacking diligence in financial transactions.

The hearing was then adjourned. A decision is scheduled for the end of the month.

Prosecutors alleged that the bankers failed to sufficiently determine the identity of the owner of the funds.

Public prosecutor Jan Hoffmann said that around 30 million Swiss francs ($31.84 million or €30.22 million) were involved in the case.

"All the evidence runs contrary to Sergey Roldugin being the real owner of the assets," Hoffmann said. "The bankers have not followed the rules and should therefore be punished."

Defense lawyer Bernhard Loetscher argued that doubts about the identity of the true owner of the funds were "not enough from a criminal point of view."

The defense said it was "plausible" that Roldugin had accured his wealth as a friend of Putin, benefiting from beneficial financing and unsecured loans.

What is the background to the allegations?

Roldugin was named the owner of two accounts at Gazprombank Switzerland in 2014. He had no listed activity as a businessman.

Putin has in the past said that Roldugin earned some money from a minority stake in a Russian company. The Kremlin has previously dismissed claims that the funds are linked to Putin.

In 2016, the Panama Papers alleged that friends of Putin's funneled millions abroad and financial employees may have turned a blind eye to the funds.

The cellist ended up on the sanctions list of a number of Western states, including Switzerland, following Russia's invasion of Ukraine in February 2022.

The US Treasury Department describes Roldugin as "part of a system that manages President Putin's offshore wealth."

It is "publicly known that Russian President Putin officially has an income of just over 100,000 Swiss francs and is not wealthy, but in fact has enormous assets managed by people close to him," the indictment at the Zurich District Court said.

sdi/ar (AP, Reuters)