LONDON, Oct 19 (Reuters) - The brother of a suicide bomber who killed 22 people in Manchester in May 2017 has left Britain ahead of a scheduled appearance on Thursday at a public inquiry investigating the attack, the inquiry was told on Tuesday. Salman Abedi blew himself up at the end of an Ariana Grande concert at the Manchester Arena venue, as parents arrived to collect their children. Among those killed were seven children, the youngest aged eight, while 237 people were injured. His brother, Hashem Abedi, was found guilty of murder and jailed for at least 55 years in August 2020 for helping Salman plan the attack. The two men"s older brother, Ismail Abedi, had been summoned to appear on Thursday before the public inquiry, which has been running for more than a year to examine issues raised by the bombing. "We understand that he is not currently in the country, and there is no indication as to when he will return," said Paul Greaney, counsel to the inquiry, at Tuesday"s hearing, urging Abedi to make contact with the inquiry"s legal team. "As he surely must understand, if he does not do so, the public may infer that he has something to hide." The inquiry, chaired by retired High Court judge John Saunders, is seeking Ismail Abedi"s evidence as part of its investigation into his brothers" motivations for the attack. Abedi, who was detained and questioned by police following the bombing and then released without charge, has so far refused to cooperate with the inquiry, arguing he did not want to incriminate himself. The brothers were born to Libyan parents who emigrated to Britain during the rule of Muammar Gaddafi. The parents and their younger children are in Libya and are also refusing to cooperate with the inquiry, Greaney said. The inquiry is also seeking evidence from a friend of Salman Abedi, Ahmed Taghdi, who has been summoned to attend on Thursday. Greaney said Taghdi was arrested on Monday as he tried to leave the country, and was currently in custody.