The complicated case stems from Matthew Parish’s decision to report his clients — both oil traders — to the authorities amid a dispute about a $750,000 legal bill. The two clients, Murat Seitnepesov and Konstantin Ryndin, contended in a criminal complaint that triggered the prosecutors’ investigation that Parish offered to withdraw the allegations if he was paid in full. To back up their claim, they cited an email Parish sent them in which he made the pledge.

Geneva prosecutors said in a statement that the indictment was issued on Jan. 30.

Parish, a British citizen, said in an email to Bloomberg that he felt “obliged under my national laws on counter-terrorism, anti-money laundering and national security” to file the reports. He said he has given his lawyer hundreds of thousands of documents that back up his claims.

“I am disappointed that I am being prosecuted by the Geneva authorities for complying with my legal obligations,” said Parish, who denies any wrongdoing.

Prosecutors said they couldn’t release a copy of the indictment until closer to trial, a date for which hasn’t been set. A conviction on extortion charges carries a prison sentence of up to 10 years under Swiss law, while those found guilty of defamation in Switzerland typically face a fine.

Amid the allegations of extortion, the case offers a rare glimpse into the publicity-shy world of commodity trading in Switzerland. The Alpine nation is home to some of the biggest commodity trading houses as well as scores of smaller niche players operating in challenging parts of Africa, Central Asia and the Middle East.

Parish reported his clients to American and U.K. authorities after they failed to pay 777,413 Swiss francs ($777,500) in legal fees he said he was owed. In March 2018 Parish wrote to the U.K.’s MI5 and the U.S. Office of Foreign Assets Control, accusing Seitnepesov and Ryndin of “being responsible for one of the greatest frauds in recent history in terms of the misuse of shell companies,” according to the Russians’ initial criminal complaint against Parish.

According to the complaint, Parish said in his letter to MI5 that Seitnepesov, the managing director of Integral Petroleum SA, “runs a sophisticated fraudulent array of offshore companies as part of his oil trading business, the purposes of which are or have been to evade” sanctions on trading with Iran and “to conceal the fact that he is transacting with sanctioned persons or entities” in Russia and Iran.

The two Russians said in their initial criminal complaint that they were “stunned” when Parish billed more than 720,000 francs for “periodic consultation” work in just two months of 2017.

“Seeking to frighten us in order to force us to pay the amounts we allegedly owe him, Mr. Parish has not hesitated to sully our reputation by spreading libelous information,” according to the complaint.

David Bitton, the Russians’ lawyer, declined to comment on the indictment against Parish.

Authors: Andy Hoffman and Hugo Miller