Omer was captured by Iraqi security forces last week after civilians in Mosul reported his hideout to security forces.
In a 2015 video clip, Omer – known as “white beard” – is shown addressing a crowd before three men accused of homosexuality and blasphemy are forced to their knees and beheaded.
However, Clarion Project is reporting that Omer was arrested and released just minutes later after paying the bribe in a police station in Mosul.
Local official Zuheir Hazzen el-Jaburi said:
“I was in Mosul when a force from police intelligence arrested a man. After questioning they were told he was the mufti for the right bank of the [river in the] city – an ISIS member.
“We asked people who he was, and they proved he really was ISIS' mufti. After he was arrested, he left a motorbike behind. An hour later we saw the motorbike was no longer there.
“We inquired about it. They said he was released 10 minutes earlier after he paid 75 notes [$7,500].”
El-Jaburi added that this type of corruption is rife in Iraq.
In 2016, ISIS threw a 15-year-old boy from a roof after he was discovered engaged in a sexual act with an IS leader.