A Karachi Sessions Court acquitted MQM-Haqqiqi Chairman Afaq Ahmed for lack of evidence on Wednesday.
Afaq was found guilty for posessing illegal weapons and explosives earlier this month.
Karachi Police on the June 8, 2004, seized several automatic weapons, bullets and grenades from Afaq's house in Landhi.
The police accused Afaq of using these weapons in violent acts in the city.
Wednesday's hearing was heard in Karachi Central Jail where Additional District and Sessions judge Ubaid Hamza Khan acquitted Afaq, citing lack of evidence.
Afaq was also presented in the court.