Police said Tuesday he lived in east London and that his family has been notified, adding that he was not considered to be a "subject of interest" to either police or the intelligence services.
The Islamic State terror group, also known as Daesh, has claimed the London Bridge rampage, while the attack has sparked fears Britain is in the grip of a spate of copycat incidents.
Zaghba was stopped while trying to take a flight to Turkey on his way to Syria, Italian newspaper Corriere della Sera reported Tuesday.
"Inquiries are ongoing to confirm the identity of their accomplice". Within minutes, the attackers are shot dead and another police vehicle arrives as people are seen running for their lives.
Mr. Shafiq said he was "not surprised" Butt went on to carry out the attack last weekend, and argued the authorities have "serious questions" to answer.
Britain's response to the terror threat must change, she said, after the three attacks which in total left 34 dead and some 200 injured.
"People are going to look at the front pages today and they are going to say, 'How on earth could we have let this guy or possibly more through the net?"
Police have named the attackers as Khurum Butt, 27, who had been known for his extremist views; 30-year-old Rachid Redouane, also known as Rachid Elkhdar; and Youssef Zaghba, a 22-year-old Italian national of Moroccan descent who was reportedly working in a London restaurant.
Security measures were heightened on Thursday as millions headed out to vote in the general election. The second man, Rachid Redouane, had not aroused any suspicions. Transport for London confirmed he worked for London Underground in customer services before leaving last October. In a letter posted outside Tuesday, the Ummah Fitness Centre said staff would "help the police in any way we can".
As these details have emerged, Prime Minister Theresa May has faced questions about her record overseeing cuts to police numbers when she was interior minister. The attackers were shot dead by police.
The latest opinion poll, by Survation for ITV, showed the Conservatives' lead narrowing to just one point from six points in the same poll a week earlier.
He was drinking at the Boro Bistro near Borough Market when the area came under attack. Much of the area around London Bridge remained cordoned off as commuters struggled to work in the driving rain.
With flags at half-mast, the nation fell silent at 11:00am (1000 GMT) to remember the seven killed and dozens injured on Saturday night - a mourning ritual now grimly familiar after two previous terror attacks in less than three months.
A source briefed by an Irish counterterrorism official told CNN that one of the London attackers had a connection to Ireland after state media reports that an Irish ID card was found on the body of one of the London attackers.