A video circulated in social media showing the torture of Libya's Colonel Gaddafi's son has drawn deep concern of the UN and international rights organizations.

The UN mission to Libya voiced deep concern over the video in which Gaddafi's son Saadi was tortured and tied to a pipe by the prison guards.

Saadi Gaddafi, the son of late dictator Colonel Gaddafi fled abroad during Libya's revolution in 2011.

State prosecutors in Tripoli are attempting to identify the guards in a video that appears to have been filmed in the al-Hadba prison.

The film appears to show guards goading and beating the man who was extradited to Libya by Niger last year. It was posted a week after a Tripoli court sentenced another of Colonel Gaddafi's sons, Saif Al-Islam, and eight former regime officials to death over crimes during the 2011 uprising that toppled his father.

Meanwhile, Human Rights Watch asked the Libya authorities in charge of al Hadba prison to launch investigation into the mistreatment of prisoners, including Gaddafi's son.

Meanwhile, Libya's National Committee for Human Rights strongly condemned the violations against prisoners which are directly under the supervision of the judicial bodies.