Pastor Yousef Nadarkhani of the Church of Iran, the country's largest house church movement, and his wife Tina Pasandide Nadarkhani have been released from detention after being detained on Friday but three other church members remain in custody, a senior church official told BosNewsLife on Saturday.

The pastor, who in the past faced a death sentence for apostasy before being acquitted and released in 2012, was among several Christians detained in the city of Rasht on 13th May by agents of Iran's Ministry of Intelligence, said Firouz Khandjani, a council member of the Church of Iran.

"However three men, Yasser Mossayebzadeh, Saheb Fadaie and Mohammadreza Omidi remain detained," he added."We are now investigating what the charges are against them," explained Khandjani. The Church of Iran has often been targeted by authorities who view the movement as a threat to Islam. Members include many former Muslims.

The latest arrests also came amid fresh concerns over the health of Church of Iran Pastor Behnam Irani, who has been behind bars since 2011 on what his supporters view as trumped-up security charges linked to his Christian activities.

Activists have told BosNewsLife that he is still in prison and suffering from a still unknown sickness. "The pastor is coughing, sometimes he will cough for 5 to 10 minutes straight," said Present Truth Ministries (PTM), a mission group supporting the pastor.