The family of a British man arrested in Pakistan for "posing as a Muslim" are calling for the government to help bring their father back to the UK.
Masood Ahmad was jailed in November on blasphemy charges after being secretly filmed reading from the Koran.
The dual Pakistani-British national, 72, belongs to the minority Ahmadiyya sect, considered heretics in Pakistan.
They were declared non-Muslim in 1974 by the Pakistan government and have restricted religious practices.
This is because of theological differences with mainstream Islam.
One of the restrictions on their religious freedom is that they cannot publicly quote from the Koran.
Two men posing as patients visited Mr Ahmad at his clinic in Lahore, before asking questions about religion.
They used a mobile phone to secretly film him reading the Koran and then called the police to have him arrested.
Ahmadis can be jailed for up to three years in Pakistan for referring to their faith as Islam, preaching or "outraging the religious feelings of Muslims".
Mr Ahmad's daughter, Aasiya, who lives in Glasgow, said she was distressed by what had happened.
She said: "My father didn't hurt anybody. We just want him out of jail and with us here where he can practice his faith freely."
Mr Ahmad had several operations to remove a tumour in 2010 and his family is concerned that his health will deteriorate in prison.
His lawyers have applied for bail due to his age and illness, but have been unsuccessful on three occasions.
The Foreign Office do not usually get involved in cases between dual Pakistani-British nationals and authorities in Pakistan but according to advice given to individuals detained there, it "may make an exception to this rule".
Mr Ahmad's son, Abbas, said he wanted the British government to put further pressure on the Pakistani authorities.
"They say because he has dual nationality, they have limited access for these kinds of things. For us, his children are here, he's a British citizen. We are taxpayers, he's paid tax.
"My father is 72 and he's never harmed anybody. Anyone can read the Koran - a Muslim, a Christian, anyone. We just want the government to help."
In response, a spokesman for the Foreign Office said: "We cannot get British nationals out of prison or detention, nor get special treatment for them because they are British.
"We urge the government of Pakistan to guarantee the fundamental rights of all its citizens."
The spokesman added: "We engage at a senior level on the issue of the mistreatment of religious groups, including Ahmadis.
"We will continue to provide consular assistance to both Mr Ahmad and his family".
In an interview with the BBC from his prison last month, Mr Ahmad said he felt targeted prior to his arrest and was concerned about how his children were coping.
Mr Ahmad's family is trying to stay hopeful that he will soon be released from prison.
Aasiya Firdous said: "We are trying to do our best and stay strong for each other. We knock on every door we can. We are just looking for the good and trying to stay positive."
Listen to more on this story on BBC Asian Network on Friday 10 January at 13:00 GMT and 17:00 GMT.