A man who was filmed apparently being choked by a police officer during an arrest believed he was going to die.
A video of the arrest, shared on social media, shows Hassan Ahmed being held on the ground with an arm around his neck.
The 27-year-old, from Halifax, has since been released under investigation and says he was not resisting arrest.
The officer involved has been suspended by West Yorkshire Police pending an investigation
Mr Ahmed said: "I was afraid for my life, I thought 'that's it, he's going to end up killing me'.
"I honestly thought it was my final moments, I was in shock, I was really scared."
He said the arrest came after he was called to the area by a family member and got into a argument.
"He did push me as if he were going to arrest me, I complied, I didn't resist him, I complied all the way. I even had my hand by my sides."
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During the video, a voice can be heard saying "chill out or I'll choke you out, chill out or you're going to sleep".
Mr Ahmed is seen tapping on the floor and another voice can be heard saying "I give up" before he is told to "turn over now", with another officer helping to detain him.
"I was just thinking about my family, I thought 'He's not going to let go, he's going to keep going, he's going to finish me'," Mr Ahmed said.
"I was in pain, I couldn't breathe, I couldn't feel anything, I couldn't even gasp for air.
"He carried on, then he punched me in my face."
Mr Ahmed says the incident has left him unable to sleep or work.
Image caption Protesters gathered earlier and marched passed Halifax police stationHis sister Safyah, earlier joined a demonstration outside Halifax police station by about 100 protesters.
She said she had felt sickened when she saw the video.
The protesters carried signs which read "Stop police brutality" and "You're not above the law".
"It's obviously struck a chord with everyone from every background," Safyah said.
West Yorkshire Police said the officer involved had been suspended pending an investigation.
The Independent Office for Police Conduct (IOPC) also confirmed the incident had been referred to them.
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