The charity Release International has linked this to a rise in Islamic nationalism across central Asia in places like Tajikistan.
Pastor Batyr fled Turkmenistan after being arrested and tortured 18-years-ago for talking about Jesus.
Speaking through a translator, he told Release the situation there remains tough.
"The totalitarian control over all leaders and churches goes on.
"Freedom of movement and freedom to preach the gospel is not allowed. Turkmen and Uzbek churches never get official registration and the state doesn't want to recognise Christians."
Security police in Tajikistan arrested and fined ten Christians last for handing out gospel literature.
Release International said the group had gone to the Pamir Mountains to give out tracts and were fined about £750 - more than most Tajiks would earn in six months.
In neighbouring Kazakhstan, a new religious survey has found that 263 people were punished in 2017 for hosting religious meetings, offering religious literature and other offences.
The authorities prosecuted 30 Christians for sharing their beliefs, according to Forum 18. Most of those prosecuted for 'religious crimes' were Protestants.
Highlighting the persecution Muslim converts face, Pastor Batyr said: "We become enemies of the people.
"They [Muslim converts] suffer more than all and are persecuted more than all."
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