MI5 has launched a second investigation into claims that the Manchester bomber was repeatedly flagged to authorities for his extremist views.
The British domestic intelligence agency was facing pressure after it emerged that Salman Abedi's friends, family and members of his mosque all raised concerns about the attacker with the Home Office and anti-terror hotlines.
Intelligence officials also knew of Abedi's links to a militant Islamist group in Libya – titled the Libyan Islamic Fighting Group (LIFG) – and to Isis-linked jihadists in the UK, but still took no action to detain the 22-year-old.
It also emerged that the FBI warned MI5 that Abedi was part of a terror cell in the north west of England that was plotting an attack in the UK, but Abedi was still allowed entry into the UK from Libya days before launching his attack, which killed 22 people.
In response to the pressure placed on MI5, security officials justified the lapse because they said 500 terror investigations were ongoing and that over 3,000 people were being monitored at any one time.
However, after launching an initial inquiry, Rudd confirmed on Sky News on Sunday (29 May) that MI5 will launch into a more in-depth investigation into why intelligence was missed.
Despite the first step, it was questioned why MI5 should be allowed to investigate itself after making the blunders, rather than an independent body.
BBC Newsnight reported that when Abedi was 16 he fought against the Muammar Gaddafi regime with his father.
The investigation comes as rebels now living in England claim that the UK Government waived travel bans to let them fight in Libya, according to the Mail Online.