Ulugbek Madaliyev, 32, and Azim Rakhmonov, 29, were detained in Khudzhand, an administrative center in northern Tajikistan, for propagating illegal material in 2004, the source said.
Two CDs containing reports on the organization's activities were confiscated from Madaliyev and a criminal investigation has been launched.
Tajik law enforcement bodies have detained more than 20 Hizb-ut-Tahrir members since the beginning of this year.
Hizb-ut-Tahrir al-Islami, a Sunnite religious and political organization, was set up in the middle of the 20th century. Its purpose is to form a world caliphate, or Islamic government, by means of jihad, or holy war, and bring Muslims back to Shariah, the Islamic law.
The organization spread to Uzbekistan, Kyrgyzstan and Tajikistan, where it was banned in April 2001.
