Hashem Abedi was found guilty in March of murder, for encouraging and helping his brother Salman to blow himself up at the Manchester Arena as parents arrived to collect their children at the end of a show by the U.S. pop singer. Among those killed were seven children, the youngest aged just eight, while 237 people were injured.

Hashem had denied involvement but offered no evidence in his trial. A jury concluded he was as guilty as his brother of murder.

On Monday, an independent public inquiry into the bombings was told he had acknowledged his role during an interview with lawyers.

“On the 22nd of October... Hashem Abedi admitted that he had played a full part, and a knowing part, in the planning and preparation for the arena attack,” lawyer Paul Greaney, who is counsel to the Manchester Arena Inquiry, said.

Abedi was jailed for life in August and told he must serve at least 55 years behind bars.

The brothers, born to Libyan parents who emigrated to Britain during the rule of late leader Muammar Gaddafi, had plotted the attack at their home in south Manchester, shortly before they returned to Libya in mid-April 2017.

Hashem remained in Libya while his 22-year-old brother carried out the bombing. Police said Hashem had persuaded acquaintances to buy chemicals to make the explosives and had sourced metal drums used to build prototype devices.

Figen Murray, the mother of one of the victims, Martyn Hett, said it would have been more bearable for bereaved families if Hashem had confessed in court.

“Abedi admitting his guilt does not come as a relief. It does not change what happened or the outcome of the sentencing,” she said in a statement.