Andy Hall, a migrant rights activist assisting the defence team, said the main thrust of the appeal relates to issues with the forensic evidence.
Lawyers for two Burmese migrants facing the death penalty in Thailand said their appeal will be submitted to the court next Monday.
A Thai court has given lawyers for two Burmese migrants convicted of killing British tourists in 2014 until 23 May to file their appeal.
The re-enactment was carried out under heavy security with dozens of police and military personnel, and drew a large crowd of bystanders.
As testimonies conclude, Win Zaw Htun claims he was sexually abused by Thai police officers and forced to confess.
Burmese suspect testifies he was handcuffed, had a bag placed over his head, and was beaten, before police threatened to extract his teeth with pliers.