[3] That year, he was a party to Rasul v. Rumsfeld, which sued the United States government and the military chain of command for its interrogation tactics.

[3] American troops discovered al-Harith among numerous foreigners held by the Taliban in jail in Kandahar and released him.

Al-Harith was detained in Kabul by US forces who found his explanations regarding the purpose of his travels in the region to be implausible.

He was arrested as a suspected enemy combatant and transported to Guantanamo Bay detention camp, where he was one of nine British citizens detained.

He was interviewed by representatives of MI5 and the British Foreign Office, as well as by US officials, and, according to US interrogators, he provided them with useful information about the Taliban's methods.

[3] In March 2004, al-Harith was among five British citizens, including the Tipton Three, who were released and repatriated to the United Kingdom.

They charged that illegal interrogation tactics, including torture and religious abuse, were permitted to be used against them by Secretary Rumsfeld and the military chain of command.

It dismissed the case in 2009 on the grounds of "limited immunity" for government officials, holding that at the time in question, the courts had not clearly established that torture was prohibited in the treatment of detainees at Guantánamo.

Because of his imprisonment as a "terrorist," al-Harith had difficulty getting work in Britain despite having been paid compensation from the UK government.

[12] In February 2017, IS announced that al-Harith had been killed when he carried out a suicide car bombing at an Iraqi army base in Tal Gaysum, southwest of Mosul.

[4] Reuters cited three anonymous Western security officials, who claimed that it was likely that al-Harith was the suicide bomber.