Khuram Shazad Butt, who was killed by police along with his two accomplices after killing seven people and leaving dozens wounded on London Bridge, had appeared in a 2016 British television documentary called "The Jihadis Next Door".
Khuram Shazad Butt, a 27-year-old British citizen born in Pakistan, and Rachid Redouane, who claimed to be Moroccan-Libyan, were named as attackers on Monday evening.
The department adds that while Butt "was known to the police and MI5", the agencies had no reason to believe he was involved in planning the attack.
The police yesterday named two of the men who carried out Saturday night's terror attack in London.
The three assailants were all shot dead by responding officers less than eight minutes after they were first called.
Police said they had to prioritize resources on suspects who were believed to be preparing an attack or providing active support for one.
But May's own record came under fire from Labour, which - according to opinion polls questioned for their reliability - has closed the gap on her Conservatives ahead of Thursday's election.
Butt, who reportedly went by the name Abu Zaitun, was known to neighbours by the nickname "Abs/z" and was allegedly an associate of radical hate preacher Anjem Choudary.
South Africa start off tournament with a comfortable win
Dickwella disturbed the lines by making room and found boundaries either side of the pitch, slashing and swatting with disdain. And three balls later Chamara Kapugedera was lbw first ball to Tahir's googly, never the greatest end for an global batsman.
He appeared in a Channel 4 documentary entitled "The Jihadis Next Door" about British extremists that was broadcast a year ago, local media reported.
Redouane was not known to those authorities.
He returned to Ireland again in 2015, again for an unknown length of time, but Taoiseach Enda Kenny said he was not one of a small number of radicals under surveillance.
"We have given increased powers to the police to be able to deal with terrorists - powers which Jeremy Corbyn has boasted he has always opposed", she said.
"To the sick and evil extremists who commit these ugly crimes, we will defeat you.
From Saturday until now my focus has been dealing with the aftermath of the horrific attack". "We have constant attacks going on, not just there but across the globe, and we have to start putting national security and global security at an all time high", she told a White House briefing. "You will not win".
Prime Minister Theresa May has come under fire for her role reducing ranks of cops.
Before the recent attacks, Brexit and domestic issues such as the state of the health service and the cost of care for the elderly had dominated the election campaign.