Muhammadrafiq Kamalov, also known as Rafiq Qori Kamoluddin, was killed in a joint Kyrgyz-Uzbek security raid in Osh along with two other men whom authorities have identified as Tajik citizens.
Among those who gathered at Kamalov's house was his son Rashod. He accused the Kyrgyz government of harassing his father.
"They [first] tried to imprison him. Then the people protested and they got scared. Now they put a gun in his hand and shot him dead," he said. "He is a shahid [a martyr.] They got rid of my father. They got scared of him because he had 20,000 or 30,000 followers. I will meet with my father in paradise."
Kyrgyz authorities say Kamalov was killed while resisting arrest and claim he was a member of the banned Islamic Movement of Uzbekistan (IMU).
Citing weapons and munitions allegedly found in his car, they say Kamalov and his two companions were plotting terrorist attacks.
Kamalov's relatives deny the charges.
Kamalov was known for allowing members of another banned radical religious group, Hizb ut-Tahrir, to pray at his mosque. He was, though, critical of the group, which seeks to establish a caliphate in Central Asia through nonviolent means.
Kyrgyz security officers in May detained and questioned Kamalov about his alleged links to Hizb ut-Tahrir. But they then made no mention of his purported links with IMU.