The younger brother of Manchester Arena bomber Salman Abedi is being extradited from Libya to the UK.
Hashem Abedi was arrested in the country a day after the May 2017 suicide attack that killed 22 people at the end of an Ariana Grande concert.
The Interior Minister’s office in Tripoli confirmed that Mr Abedi was extradited on a flight which left Mitiga Airport at 10:30 BST.
The Home Office has declined to comment.
A spokesman for the Rada Special Deterrence Force military group, which has been holding Mr Abedi, said he was handed over to members of the British Embassy.
Sources have told the BBC Mr Abedi was on board a UK government-owned jet.
Mr Abedi, who is in his early 20s, is expected to be interviewed by British authorities upon his return.
Both brothers travelled to Libya in April 2017, before Salman Abedi returned alone to carry out the attack on 22 May.
Twenty-two people died in the bombing while a total of 112 needed hospital treatment after the attack.
Greater Manchester Police (GMP) was granted a warrant for Mr Abedi’s arrest in November 2017.
It said the warrant related to the “murder of 22 people, the attempted murder of others who were injured and conspiracy to cause an explosion”.
A Libyan court had previously agreed to extradite Mr Abedi to the UK because he is a British citizen but the extradition process was delayed by fighting in Libya.
No-one has been charged over the Manchester Arena attack despite police raids after the bombing.
A 2018 report said 23 people arrested in the UK were all released without charge.