UNITED NATIONS (AP) — Lawyers for Wall Street Journal reporter Evan Gershkovich asked a United Nations body on Tuesday to urgently issue an opinion that he has been arbitrarily detained by Russia on espionage charges which are “patently false.”

The request to the U.N. Working Group on Arbitrary Detention says “Russia has failed to produce a shred of evidence in support of its accusations” since the 31-year-old journalist was arrested on March 29 on a reporting trip to the city of Yekaterinburg, almost 2,000 kilometers (1,200 miles) east of Moscow.

“Russia is not imprisoning Gershkovich because it legitimately believes its absurd claim that he is an American spy,” the Journal’s request said. “Instead, Russian President Vladimir Putin is using Gershkovich as a pawn, holding him hostage in order to gain leverage over – and extract a ransom from – the United States, just as he has done with other American citizens whom he has wrongfully detained.”

Jason Conti, executive vice president and general counsel of Dow Jones, which publishes the Journal, told a news conference at the U.N. Correspondents Association the paper hopes for an opinion stating that Russia hasn’t lived up to its obligations under international law and urgently demanding his release.

The Working Group on Arbitrary Detention, comprising five independent experts, is a body of the Geneva-based U.N. Human Rights Council. It has a mandate to investigate cases of deprivation of liberty imposed arbitrarily or inconsistently with the international standards set forth in the Universal Declaration of Human Rights.

The Russian Foreign Ministry has previously said it would consider a swap for Gershkovich only in the event of a verdict in his trial. Espionage trials in Russia can last for more than a year, and no date has been set.

Gershkovich’s legal team in Russia has appealed a Moscow court’s decision to extend his pretrial detention until the end of November.

Paul Beckett, the Journal’s Washington bureau chief, told reporters that Gershkovich is “doing pretty well under the circumstances,” saying he is young and healthy, has been able to send and receive letters, and is visited by his lawyers and occasionally U.S. diplomats.

Gershkovich is the first American reporter to face espionage charges in Russia since September 1986, when the KGB arrested Nicholas Daniloff, a Moscow correspondent for U.S. News and World Report.

Mariana Katzarova, the first U.N. special investigator on human rights in Russia, told the press conference that Gershkovich should be released immediately because he was arrested “for the exercise of his profession as a journalist.”

Last year, she said, 16 people were convicted on charges of espionage and treason in Russia, but in the first seven months of this year 80 people have been charged with treason.

“I think it’s a massive escalation of the use of these charges to really silence independent media, but also any anti-war expression, any independent opinion,” Katzarova said.

She said her first report on the human rights situation in Russia will be presented to the Human Rights Council on Sept. 21.