I think it's highly dependent on the lie to be honest. The ethics argument on psychological experiments should be applied to this too, if the lie is going to cause the prisoner lasting emotional damage then no it shouldn't be done. However if it's a little white lie that you use to test the waters or corroborate the persons story then by all means go ahead. Also, lying should definitely not be used to blackmail the prisoner into confession.

I'm an 18 year old Sociology student.