A Moscow court on Tuesday rejected an appeal by American journalist Evan Gershkovich to extend his pre-trial detention in an espionage case that he and US authorities have rejected as false.

Gershkovich, 32, a reporter for The Wall Street Journal, has been in Moscow's notorious Lefortovo prison for more than a year after being arrested while on a reporting trip to Russia.

He is the first Western journalist since the Soviet era to be arrested by Moscow on espionage charges – charges he, his employer and the US government deny.

“The First Court of Appeal ruled that the decision of March 26, 2024 to extend the preventive measure should be left unchanged,” Judge Alexander Pushkin said at a hearing on Tuesday, an AFP journalist reported from the court.

The hearing was a technical appeal of an earlier decision to keep Gershkovich in custody until at least June 30 pending trial, and did not address the merits of the case.

The reporter, who previously worked for AFP and The Moscow Times in the Russian capital, stood on a glass partition in the courtroom wearing dark trousers, a white T-shirt and a dark shirt.

He smiled and gave a thumbs up when a reporter asked him how he was doing.

Moscow has not provided any public details of its case against Gershkovich, saying only that he was "caught red-handed" in the Ural city of Yekaterinburg last March.

Russia said a possible prisoner exchange involving Gershkovich was being discussed behind the scenes.

President Vladimir Putin has publicly signaled that Moscow would like to secure the release of a man Germany says was working for the Russian state when he killed a Chechen rebel commander as part of a deal to free Gershkovich.

Washington has repeatedly accused Moscow of arresting US citizens to use them as pawns to free Russians jailed abroad for serious crimes.