Secretary of State Hillary Clinton has taken a personal interest in the case of an American citizen who U.S. officials say has been abused in prison in Belarus, an aide said Thursday.

Acting State Department spokesman Robert Wood told reporters that Clinton "is focused on" the case of Emanuel Zeltser, the Russian-born lawyer from New York who has been in custody in Minsk since March of last year. Clinton "wants to know what we can do to help," Wood said. 

FOX News reported exclusively on Wednesday that U.S. officials believe Zeltser has been subjected to "abuse in prison," and that they have been formally protesting the abuse to the Belarusian government. 

"We don't use the word lightly," Wood said, adding the determination had been made based in part on "discussions that we have had with Mr. Zeltser." Wood also suggested Belarusian mistreatment of Zeltser may be recurrent, as the spokesman, using the plural form, said U.S. officials working on the case have been "protesting incidents of abuse."

On Wednesday, State Department spokesman Andrew Laine told FOX News that American embassy officials in Minsk, the Belarusian capital, had  sought to ensure "appropriate medical treatment for [Zeltser's] serious conditions" as part of their regular consular access to Zeltser. 

Zeltser has a heart condition and has reportedly been denied proper medical attention. His American doctor has said Zeltser will die of cardiac arrest if he is not transferred to an American hospital soon. The U.S. government has formally requested that Zeltser be released at once on humanitarian grounds, but to no avail in Belarus, which is Europe's last Soviet-style dictatorship.

A well known lawyer who has testified before Congress and appeared as a guest commentator on FOX News, Zeltser was arrested in Minsk last March following a trip overseas to pursue a legal and financial dispute with billionaire Russian "oligarch" Boris Berezovsky. 

Supporters of Zeltser allege Berezovsky arranged to have him spirited out of London on a private plane and transported to Minsk against his will. Last August, Zeltser was tried and convicted in a closed-door trial on espionage and other charges, at which Berezovsky testified. Zeltser was sentenced to three years in prison.

On Jan. 22, a State Department attorney met with Belarusian officials in Minsk to respond to questions they had about American contacts with Zeltser. 

"Our embassy in Minsk continues to provide full consular services for Mr. Zeltser, including regular prison visits, protesting incidents of abuse, communicating with his family, with his lawyer, and making sure that he has access to required medication," Wood said Thursday. "And we continue to call for Mr. Zeltser's release on humanitarian grounds."

James Rosen joined Fox News Channel (FNC) in 1999. He currently serves as the chief Washington correspondent and hosts the online show "The Foxhole." His latest book is "A Torch Kept Lit: Great Lives of the Twentieth Century" (Crown Forum, October 4, 2016).