Karimov, editor in chief of "Femida 007," a newspaper that covers crime and legal issues, is accused of libeling the ministry by publishing articles that claim organized crime is rising in the country.
Usubov has demanded that Karimov be arrested.
Usubov's representative in the case, Alirza Habilov, told RFE/RL that articles published in the local newspapers "Azadliq" and "Femida 007" libeled Usubov and his staff.
But Karimov says the writings, which he published after the arrest of former Interior Ministry official Haci Mammadov, merely criticized the ministry and are not libelous.
Legal proceedings were postponed until November 13 so that Karimov can review the documents of the case.