The 22-year-old Italian national, who was of Moroccan descent, came from East London where some of the Metropolitan police’s investigation has been focussed.
His name is the last to be released after the other two attackers were named as Khuram Butt, a 27-year old Pakistan-born British citizen, and Rachid Redouane, a Moroccan-Libyan pastry chef aged 30.
Scotland Yard released a statement which said: "The Met’s counter-terrorism command has released the name and photograph of the third attacker shot dead by police following the terrorist attacks on London Bridge and at Borough Market on Saturday.
"While formal identification is yet to take place, detectives believe he is 22-year-old Youssef Zaghba, from east London.
His name is the last to be released after the other two attackers were named
All three men involved in the attack were confronted and shot dead
"The deceased's family have been informed.
"He is believed to be an Italian national of Moroccan dissent. He was not a police or MI5 subject of interest.
"All three men involved in the attack were confronted and shot dead by armed officers within eight minutes of the first call."
The trio ploughed into crowds before going on a stabbing frenzy
The trio ploughed into crowds before going on a stabbing frenzy around London Bridge and Borough Market, leaving seven people dead and dozens injured.
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Police confirmed he was not a person of interest to the police or known to intelligence agency MI5.
As the terror probe continues another man 27-year-old man was arrested in Barking on Tuesday.
More to follow . . .
London Bridge terror: Scenes as armed police respond Sun, June 4, 2017
At least two people have died after being after reportedly being struck by a van on London Bridge on Saturday night.
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Armed police responding to the incident at London Bridge