Iraq's justice system freed a commander of the Popular Mobilization Forces (PMF) on Wednesday, two weeks after he was arrested over the murder of an anti-government activist.
Qassem Muslih was arrested by police intelligence on suspicion of ordering the May 9 killing of Ihab al-Wazni, who was shot dead by men on motorbikes using a silencer.
Muslih was welcomed by pro-Iran PMF colleagues in Iraq's Karbala city following his release, AFP journalists said.
"The judges have served justice, they have ended their investigation, terminating it with my release," Muslih said.
Iraq's Supreme Judicial Council said in a statement that it had found "no proof of his involvement", and that it had established "that he was not in Iraq at the time of Mr. Wazni's assassination".
But a senior official decried the decision to release Muslih.
"The government presented all available evidence, but the judges have decided to release him because of pressure exerted on them," said the official, who wished to remain anonymous.
In the wake of Muslih's arrest, security forces had barred entry to Baghdad's high-security Green Zone -- home to the US embassy, parliament and the premier's office -- after the PMF quickly deployed armed men and armored vehicles in a show of force.
Muslih is also suspected of ordering the assassination of another activist, Fahim al-Taie, in December 2019.
"Telephone communications on the topic of these assassinations between Muslih and the direct perpetrators, threats to relatives, witness testimony, explanations received under questioning -- all (these things) were supplied" to the judges, the official added.
The evidence implicated Muslih in the assassination of both Wazni and Taie, the official said.
In the same city where supporters of Wazni had last month gathered around his coffin shouting "Iran out!", Muslih was Wednesday greeted as a hero.
"Qassem has returned victorious!" proclaimed banners brandished by supporters who threw sweets in the air.
"This is one more victory for the PMF against those who target it here and abroad," said Saad al-Saadi, a PMF official in Karbala.
Anti-government activists are often portrayed as foreign stooges by Iraq's pro-Iran factions.