On Monday, the court listened to the testimonies of witnesses for Andrew Brunson, but three of his witnesses were refused permission to testify on the grounds that they were also suspects in the case.
Steven Carter from religious freedom charity Middle East Concern tells Premier there's no evidence to prove he's guilty.
"The things that have been said - the evidence that has been brought, really seems to be farcical and would be laughable if the implications weren't so severe for Andrew," he said during Premier's News Hour.
Brunson was jailed in December 2016 over alleged ties with the Fetullah Gulen movement; an organisation authorities believe was connected with a failed coup in Turkey the summer before.
Gulen, who's in the US, is a well-known political opponent of Turkish President Recep Tayyip Erdogan.
He has consistently denied the accusations.
The US Commission on International Religious Freedom said in a statement that it was concerned by the court process that was "dominated by wild conspiracies, tortured logic, and secret witnesses, and secret witnesses, but no real evidence to speak of".
Carter told Premier Turkish church leaders have been showing the pastor support during the trial.
He said: "One of the great encouragements for Andrew yesterday at the trial was the presence of a number of other Turkish church leaders.
"He has been encouraged by the support of very many and it was wonderful to see other Turkish church leaders in a very public show of support."
Listen to Steven Carter speaking with Premier's Cara Bentley:
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