By Gleb Bryanski

MOSCOW, Feb 12 (Reuters) - A Russian lawyer who represented U.S. teacher Marc Fogel in negotiations over his release said a lack of support from the administration of former U.S. President Joe Biden had delayed his release while his health deteriorated in prison.

Fogel, 63, was serving a 14-year sentence for drug smuggling after being caught at a Moscow airport in 2021 with a small amount of marijuana. He was freed on Tuesday and flown to Washington, where he celebrated his release with President Donald Trump at the White House.

"The main difficulty was the lack of interest in our client's case by the previous U.S. administration," the co-founder of Russian law firm EPAM, Dmitry Afanasiev, told Reuters.

"This is evidenced by the last-minute designation of our client as 'wrongfully detained' only a few days before the election day and only after a public pressure campaign by the client's family and our American colleagues."

Afanasiev said the lack of the U.S.-designated "wrongfully detained" status was the reason why Fogel was not included in a previous exchange in August 2024 that involved 24 prisoners, including Wall Street Journal reporter Evan Gershkovich.

That determination clears the way for the State Department offices and federal agencies to work together to develop a plan to secure the release of a detainee.

At the time Biden said his administration "was not giving up" on Fogel's case. Anne Fogel, the teacher's sister, told U.S. media then: "Marc has never been prioritized...it's been very difficult for us to get our man out".

Afanasiev said Fogel had a chronic medical condition and his health had deteriorated fast in prison. The prison's administration allowed him "relatively unrestricted access" to provide Fogel with medical attention.

"Marc is not well... he has received several hundred pain management injections while in prison," Afanasiev said.

He said Fogel's case began to receive attention when lawyers for U.S. law firm Boies Schiller Flexner, partnering with EPAM for Fogel's release, escalated it to Trump's campaign camp.

His elderly mother planned to raise her son's plight at a campaign rally in Pennsylvania in July last year in which Trump survived an assassination attempt.

(Reporting by Gleb BryanskiEditing by Ros Russell)

((gleb.bryanski@thomsonreuters.com;))