BBC: Iranian TV has shown the first pictures of two Iranian American academics - Haleh Esfandiari and Kian Tajbakhsh - who have been held in Iran since May.
The footage was a trailer promoting a programme to be aired later this week.
Only snatches of their voices are heard but the BBC's Tehran correspondent says they appear to be confessing to trying to topple the Iranian government.
Ms Esfandiari, Mr Tajbakhsh and another detained Iranian American, journalist Parnaz Azima, are accused of spying.
They could face the death penalty if found guilty. Iran TV shows detained Americans (more)
Mark Alexander
