In the video, which is yet to be verified, Saadi appears to be beaten on the face while being questioned and later on the soles of his feet tied to a rack.
The video was posted a week after a Tripoli court sentenced Gaddafi`s son Saif Al-Islam and eight former regime officials to death over crimes during the 2011 uprising that toppled his father.
After escaping Libya in 2011, Saadi was held under house arrest in the capital of Niger, Niamey, before being extradited.
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