The third London Bridge attacker has been named as Youssef Zaghba, a Moroccan-Italian man.
Pakistan-born Khuram Butt, 27, and Rachid Redouane, 30, both from Barking were the other two attackers.
Meanwhile, another victim has been named as Australian nurse Kirsty Boden, 28, who her family said had run towards London Bridge to help people.
Seven people were killed and 48 injured in Saturday night’s attack – the three attackers were shot dead by police.
Zaghba, Butt and Redouane drove a hired van into pedestrians on London Bridge at 21:58 BST on before stabbing people in the area around Borough Market.
Armed officers killed all three within eight minutes of receiving a 999 call.
In other developments:
- All 12 people arrested on Sunday after the attack have now been released without charge
- The Metropolitan Police said a 27-year-old man had been arrested in Barking on Tuesday in connection with the investigation
- A property in Ilford, east London, was also searched by police at about 01:30 BST, but no arrests had been made, the Met said
- The Prince of Wales and Duchess of Cornwall will visit injured members of the public at the Royal London Hospital
- NHS England said 36 people remained in hospital, with 18 in a critical condition
What did police know about Khuram Butt?
Butt featured in a Channel 4 documentary last year about Islamist extremists with links to the jailed preacher Anjem Choudary called The Jihadis Next Door.
The married father-of-two, who worked for London Underground as a trainee customer services assistant for nearly six months last year, could be seen in the programme arguing with police officers in the street, after displaying a flag used by so-called Islamic State in a London park.
Two people in Barking, east London, had also raised concerns about Butt, BBC home affairs correspondent Dominic Casciani said.
One man called the anti-terrorism hotline in 2015, and a woman went to the local police because she was scared Butt was trying to radicalise her children.
Metropolitan Police assistant commissioner Mark Rowley said an investigation into Butt began in 2015, but “there was no intelligence to suggest that this attack was being planned and the investigation had been prioritised accordingly”.
The inquiry was “prioritised in the lower echelons of our investigative work”, Mr Rowley added.
Asked if that had been a poor decision, Mr Rowley said he had seen nothing yet to suggest it.
At any one time there are about 500 active counter-terrorism investigations concerning 3,000 people of interest.
Mr Rowley said work was continuing to understand more about the attackers, “their connections and whether they were assisted or supported by anyone else”.
Redouane was a chef who also used the name Rachid Elkhdar and police said he claimed to be Moroccan-Libyan. He married a British woman in Dublin in 2012 and lived in Rathmines in the Irish capital.
Who were the victims?
So far three of those killed in the attack have been named.
Ms Boden worked as a staff nurse at Guy’s and St Thomas’ Hospital in London. Her family have described her in a statement as an “outgoing, kind and generous person”.
“We are so proud of Kirsty’s brave actions which demonstrate how selfless, caring and heroic she was, not only on that night, but throughout all of her life,” they added.
The hospital said that Ms Boden was “an outstanding nurse and a hugely valued member of the staff team in Theatres Recovery, described by her colleagues as ‘one in a million’ who always went the extra mile for the patients in her care”.
Canadian national Chrissy Archibald, 30, was the first victim to be named. Her family said she had died in her fiancé’s arms after being struck by the attackers’ speeding van.
And the family of 32-year-old James McMullan, from Hackney, east London, say they believe he also died.
Mr McMullan’s sister said he was believed to be among those who died, after his bank card was found on a body at the scene.
A French national was also killed in the attack, according to foreign minister Jean-Yves Le Drian.
The Met have set up a casualty bureau on 0800 096 1233 and 020 7158 0197 for people concerned about friends or relatives.