The eight second video, which has been viewed thousands of times on social media, appears to show five police officers in a flat, two holding onto a man and one of them repeatedly hitting him on the head with what appears to be a CS spray can.
The man has his back to the wall and sinks to the ground under the blows.
Head of Professional Standards, Superintendent Matt Baldwin said: “We can confirm that the suspension of six Humberside Police officers last week is not in relation to the footage being circulated on social media.”
It later transpired that West Midlands Police (WMP) was reviewing the footage alongside that caught by their officers' body cameras.
In a tweet WMP said their Professional Standards Department would decide whether it needed to be referred to the Independent Office for Police Conduct.
Humberside Police said the six PCs had been suspended “for suspected breaches of professional standards of behaviour.”
A statement added: “Following an internal investigation by the Humberside Police Professional Standards Department we referred the case to the Independent Office for Police Conduct who have asked us to continue with the investigation under their supervision.
“The internal investigation is underway, therefore we cannot provide any further details at this point.”