NOUAKCHOTT: Abu Hafs al-Mauritani, who was a senior adviser to al Qaeda, was released from a prison in Mauritania over the weekend, his family confirmed.

Sidi Ould Walid said his brother was released after renouncing his ties to the terror network and condemning the Sept. 11, 2001 attacks.

Hafs refused to be interviewed or to be filmed as he left the prison on Saturday.

On militant forums on Monday, jihadists exchanged congratulations over the release.

Hafs was an adviser to Osama Bin Laden who helped form the modern al Qaeda by merging bin Laden's operation with Ayman al-Zawahri's Jihad.

Hafs spent years in custody in Iran before being extradited to Mauritania in April.

Walid says his brother was interrogated multiple times and his release indicates he is no longer seen as a threat.

Hafs has been largely out of the game for a decade, but the US is concerned that he could re-emerge as an ideological figure if he fails to follow through on whatever conditions of release he has made with Mauritanian authorities, a US official said, speaking on condition of anonymity to describe sensitive intelligence matters.