Ankara, Turkey - US journalist Evan Gershkovich and former US marine Paul Whelan were released from Russia Thursday, the Turkish government announced, in one of the biggest East-West prisoner swaps since the Cold War.

A total of 26 people, including two minors, from the US, Germany, Poland, Slovenia, Norway, Belarus, and Russia were involved in the swap "carried out" by Turkey's MIT intelligence service, Turkey's presidency said.

There was no immediate confirmation from US officials, although the swap was widely reported by US television networks. The Kremlin declined to comment on any exchange.

Wall Street Journal reporter Gershkovich (32) was detained in Russia in March 2023 and convicted in July on spying charges in a fast-track trial denounced as a sham by the US.

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Signs of an imminent prisoner swap had picked up momentum earlier Thursday amid reports a plane used in a previous exchange deal had landed in the Russian exclave of Kaliningrad.

Hopes had also risen in recent days after a number of high-profile prisoners in Russia, including Whelan, went missing from prisons where they were serving long terms, fueling speculation they were being moved ahead of a swap.

As a rule, swaps can only happen after a conviction in Russia, and the disappearance of several high-profile political prisoners at once is extremely rare.

Among those expected to be returned to Russia in exchange is Vadim Krasikov, a Russian citizen imprisoned in Germany for killing a former Chechen rebel commander in a brazen assassination.

The exchange would be a victory for President Joe Biden, whose vice president, Kamala Harris, faces Republican Donald Trump in the November election.

This would be the first prisoner exchange between Russia and the West since star US basketball player Brittney Griner was swapped in return for convicted Russian arms dealer Viktor Bout in December 2022.

It would also be the biggest exchange since 2010, when 14 alleged spies were exchanged between Russia and the West. They included double agent Sergei Skripal, who was sent by Moscow to Britain and undercover Russian agent Anna Chapman, sent by Washington to Russia.

Before then, major swaps involving more than a dozen people had only taken place during the Cold War, with Soviet and Western powers carrying out exchanges in 1985 and 1986.

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An aircraft already used in Griner and Bout's exchange flew from Moscow to Kaliningrad on Thursday morning, according to flight tracking website Flightradar24. The flight was later tracked taking off from Kaliningrad two hours later.

Gershkovich was arrested in the city of Yekaterinburg while on a reporting trip. He, his employer, and the US government all strongly denied the espionage allegations against him.

Biden had said after the sentencing that he was "pushing hard for Evan's release and will continue to do so."

Media rights group Reporters Without Borders said it was "hugely relieved."

"The Russian government's continued policy of state hostage-taking is outrageous. Journalists are not spies, and they must never be targeted for political purposes," the group said.

Washington has also been working for the release of jailed former Marine Whelan (54), who was arrested in 2018 in Moscow and charged with espionage.

Whelan was working in security for a US vehicle parts company when he was arrested in Moscow in 2018 and has always asserted that the evidence against him was falsified.

Also among those who disappeared was journalist and activist Vladimir Kara-Murza, a 42-year-old joint Russian and British citizen. His lawyers said on Wednesday that they did not know his location after being twice denied access to the facility where he was meant to be held.

Kara-Murza, who spoke out against the Russian invasion of Ukraine, is serving a 25-year sentence in Siberia for treason and other charges. He suffers from a nerve disease and was moved to a prison hospital earlier this month for medical checks.

Adding to the intrigue was a case in Slovenia, where a court sentenced two Russians suspected of spying for Moscow to more than a year and a half in prison – but then ordered their expulsion from the country.

Arrests of US citizens in Russia have increased in recent years, in what Washington sees as a Kremlin attempt to secure the release of Russians convicted abroad.