UPP leader Saviour Chishimba has been released from detention after police decided to discontinue the case against him.
Police Spokesperson Esther Mwaata Katongo has confirmed the development, said Dr Chishimba has been released unconditionally.
The opposition leader spent seven days in detention at Woodlands Police Station.
Dr Chishimba was picked from Diamond TV last Thursday where he had gone to record a programme and was later charged with defamation of President Edgar Lungu.
The charge arose from remarks he made during media briefing he held last month where he criticised President Lungu for asking Zambians to bear with him if he became a dictator for once.