Zaghba, 22, was one of the three perpetrators shot dead by police during Saturday's terrorist attack in central London. The 27-year-old was held under the Terrorism Act shortly after 8am on Tuesday. They have not been identified or charged.
A total of 19 people have been arrested in Britain as part of the terror probe, 12 of whom have been released without charge.
The revelation of the identity of the third man who carried out the London Bridge murders has highlighted an added global dimension to the terrorist plot, as well as raising fresh claims of a serious failure of intelligence.
After questioning him, police phoned his mother who, according to the source, said she had been anxious about her son because he had been talking about jihad.
Jibril Palomba, who lives close to Butt's east London home, said he was anxious Butt had been radicalizing kids, telling them things like, "If you are not Muslim, you do not follow in the religion of Muslim ... you're basically going to hell".
It is claimed that he knew Siddhartha Dhar, a Hindu who converted to Islam and joined Isis in Syria. She says: "When I went to England, he was a bit more rigid, but not so much".
London's Metropolitan Police said Zaghba had not been on their radar before Saturday, despite the Italian warning. He said eight other French citizens were injured in the attacks.
Two uniformed police officers were stationed outside a house in Fairfield Road, Ilford, on Tuesday evening.
Scotland Yard has named the other two terrorists involved in the London Bridge attack as Khuram Shazad Butt and Rachid Redouane.
Although news of her son's death came as a shock, she said she could only share the pain of the victims' families.
Butt, who was born in Pakistan and moved to Britain as a child, had worked in 2015 in the office at Auriga Holdings Ltd, which manages some Kentucky Fried Chicken franchises in Britain. KFC spokeswoman Jules Pars said Wednesday that Butt worked there in 2015. Reports in the Italian media said he was stopped in Bologna.
Both Butt and Zaghba were known to British law enforcement, raising questions about whether anything could have been done to prevent the assault.
Zaghba, a 22-year-old with dual Moroccan-Italian nationality, was briefly detained after being stopped at the airport in Bologna, central Italy in March 2016.
According to the reports, the British and Moroccan secret services were notified of Zaghba's status as a potential militant.
The Italian authorities had also informed their counterparts in Morocco about Zaghba.
"His computer was seized but the court that reviewed the authorisation ordered it be handed back on the grounds there was no supporting evidence for the existence of a crime".
He is said to have had one backpack with him, and a one-way ticket.
The prosecutor said Italy had lacked the evidence to prosecute Zaghba, but had warned Britain about him. "But he had Internet and that's where everything comes from", she said.
NewsGram brings to you top news around the world today.
"In fact he never lived here", said the mayor, Daniele Ruscigno. But she put much of the blame for her son's radicalization on Islamic propaganda found on the internet.
It is thought that Choudary played a key role in Butt's radicalization, according to a British government official who spoke on condition of anonymity because he was not authorized to talk about the ongoing investigation.
The fact that Butt was known to authorities before to the attacks has called into question Prime Minister Theresa May's record.
Outrage is already growing in Britain over the revelation that one of the other London attackers was a known extremist who had slipped through the net.
As details about the jihadists have emerged, May has faced questions about her record of overseeing cuts to police numbers when she was interior minister.
First announced in January, the tour launched on May 12 in Vancouver, Canada, kicking off a series of North American dates. There will be a four-ticket limit for subscriber purchases and a six-ticket limit with public sales.
The Trump Administration is said to be trying to put together a " common set of principles " from which everyone can negotiate. Abbas said the Palestinians "are committed to working with [Trump] to reach a historic peace deal between us and Israel ".
But the Conservatives confirmed that interior minister Amber Rudd would represent the party as planned at the BBC hustings. Yesterday a poll from Kantar showed the Tories' lead over Labour had stretched to 10 points.
Bert Gagnon, a retired NASA employee from Mechanicsville, Maryland, said he came to Lafayette Square to show support for Trump. Public advocate Tish James welcomed Trump's supporter, who James refers to as "Agent Orange".
According to reports, the document leaked by victor is the same one cited in an article published Monday by The Intercept . The report was published just days after Putin denied allegations that the Russian state had meddled in the U.S. election.
In times like these, we have to show love and kindness for those in need, and the Manchester One Love is a comfort to us all. We ask the strong city of Manchester and the world to join us in making the statement that hatred and fear will never win.
She choked up towards the end of the song and had to pause and compose herself before singing the last few notes. That in itself was incredibly effective, as he got nearly the entire crowd to sing along to some of his hits.
Investigators said Kushner has critical information connected to the probe, but he is not suspected of committing a criminal act. A senior administration official said Kushner was keeping his head down and focusing on work after the foreign trip.
A pair of 940nm infrared LEDs provide night vision without the telltale red glow that's typical of other security cameras. The Nest Cam IQ uses a 1/2.5-inch, 8-megapixel sensor that's capable of 4K video , paired with a 130-degree lens.
On Monday, Trump derided the revised travel ban and criticized his own Justice Department's handling of the controversial case. A Justice Department spokeswoman declined to comment to NPR's Carrie Johnson on the reports , which NPR has not confirmed.
Risks for SIDS include loose bedding, sleeping in the same bed as parents, sleeping face-down and living at home with a smoker. The study was actually about obesity prevention, but researchers found that there were differences in bedtime routines.
She played her typically safe style for much of the match, winding up with 15 fewer unforced errors than No. 8 Kuznetsova. The 26-year-old Martic next faces fifth-seeded Elina Svitolina after the Ukrainian beat Magda Linette 6-4, 7-5.
It's a co-op zombie horde mode shooter filled with tons of upgradeable weapons and tools to take down waves and waves of zombies. Of course, if you change the past, there will be some pretty serious repercussions that will change the present and future.
Mr Khan's former Labour colleague in the Commons, David Lammy, had a less subtle response to the President. He also said he was supporting his Democrat rival, Hillary Clinton, saying: "I hope she trounces him".
He has also been accused of not reporting his meeting with Putin and income from Russian sources, such as payments from RT. Megyn Kelly's highly-anticipated debut on NBC News landed with a thud on Sunday. "We didn't have any relationship at all".
Putin took advantage of the occasion to show Stone a live broadcast with the work of the Syrian combat aircraft on his smartphone. Wonder what Vladimir Putin thinks of tough women leaders such as Margaret Thatcher, Angela Merkel, Indira Gandhi and Golda Meir?
I think they know they can't keep responding in the way they've been responding. "They sense that the tone has changed", she said. Later Wednesday, Haley met with Palestinian Prime Minister Rami Hamdallah in Ramallah, her office said in a statement .
What the Climate Alliance ends up doing will determine if the actions taken count as an impermissible interstate compact. In December 2015 in Paris, world leaders signed the first global commitment to fight climate change.
But I also know where I have come from, even just 10 days or so ago. "So I like to play chess in my free time". In the women's event, France has three women in the last 16 for the first time in 23 years.
He also said that the militants involved in the act would be given "cash rewards" and warned of more such attacks in coming days. Panic gripped Wuzur and adjoining villages when the firing was followed by a "cordon and search" operation.
A ruthless Rafael Nadal permitted just one game demolishing Nikoloz Basilashvili to roar into the Roland Garros fourth round. The biggest cheer of the match came when Basilashvili , a little-known 25-year-old ranked 63, finally won a game at 6-0 5-0.
First of all, me and De La Hoya have been cool for a long time. "That's the bottom line", De La Hoya explained to BoxingScene.com. The date and place might be bogus since Saul Alvarez and Gennady Golovkin are expected to fight on the same day.
The flight crew extinguished the fire, and emergency crews were able to remove the damaged equipment after the plane landed. Homeland Security Secretary John Kelly has said the ban might expand to all worldwide flights entering or leaving the US.