A U.S. citizen being held in an Iranian prison for his Christian activities has reportedly been moved to solitary confinement, prompting concerns over his health and safety.

"We believe that he is being beaten in solitary confinement. We have no way of finding out about his health," said Naghmeh Abedini, whose husband, Saeed, has been imprisoned in Iran since last fall.

 "There will be no more visitations allowed and we will have no way of knowing how Saeed is doing," she explained.

Pastor Saeed Abedini is an American citizen born in Iran who is currently serving an eight-year sentence in Iran's Evin Prison. Raised Muslim, Abedini converted to Christianity in 2000, and after marrying an American woman, he became an American citizen in 2010.

He spent time working with house churches in Iran until the government ordered him to stop. Since 2009, he has worked exclusively with non-religious orphanages in the country.

But despite complying with the government's demands, he was arrested in the fall of 2012 during a visit to these orphanages. He was charged with posing a threat to national security through his previous work with the Christian churches, even though the churches are technically legal in the country.

Family members in Iran say that Abedini is weakened from torture and beatings and has sustained internal injuries that have not received medical treatment for months. They also warned that his kidneys may be failing.

According to the American Center for Law and Justice, which is representing Abedini's wife in the U.S., the pastor was one of a number of prisoners in his ward who signed "a letter expressing to prison officials their concern about the lack of medical care received and the threats and harsh treatment facing family members who come to visit."

In addition, the prisoners "expressed their dissatisfaction in a peaceful, silent protest in an outside courtyard at the prison."

Ten prisoners, including Abedini, were then placed in solitary confinement, and family members have said that they were turned away from seeing him, being told that he is not allowed to have visitors any longer.

Abedini "was most likely on a list of prisoners the prison wants to break," a former Iranian political prisoner told the American Center for Law and Justice.  

He suggested that the pastor was placed in solitary confinement "to put pressure on his belief and faith." 

The American Center for Law and Justice has voiced concerns that the pastor is "likely to be beaten again, in private, away from other witnesses and prisoners." Given his internal injuries, possibly failing kidney and lack of medical treatment, the group warned that Abedini is "facing perhaps his most grave situation since his imprisonment last fall."

The organization has been working for months to raise awareness and support of Abedini, calling on the U.S. government to intervene on behalf of the American citizen in the face of Iran's international law violations. More than 40,000 people have sent letters of support and encouragement to the pastor.

Abedini's wife said that the pastor had previously been placed in solitary confinement and described the experience as "the hardest time in his life."

She is now pleading urgently for prayers on behalf of her husband.

(Story continues below)

"Please pray for his health and healing. Pray for his release. Pray that the Lord would use this for His Glory and salvation of many," she said.