Lawyers for Ibrahim Halawa have accused Egyptian authorities of providing misleading information to the Irish Government about his imprisonment.
The Dublin man has been in jail in Cairo since taking part in an anti-Morsi protest in August 2013.
However, last week he was moved without the knowledge of his family.
Officials in Egypt told the Irish Department of Foreign Affairs he was in Tora Prison, when in fact he had been moved to Wadi Al Natroon.
Ibrahim's legal team say their client "somewhat disappeared" for a period of nearly 24 hours.