New Delhi: British Prime Minister Theresa May briefed the MPs in the Commons on Thursday morning and gave limited information about the man but said security services had not had any warning about the attack.
Although, the man had been investigated by the MI5 several years ago, she described him as "a peripheral figure".
Speaking at the House off Commons, Mrs May said: "His identity has been confirmed by the police and the MI5 and when operational considerations allow, he will be publicly identified".
"The man was British--born and some years ago was investigated by the MI5 over concerns into violent extremism.
"He was a peripheral figure. The case is historic.
"He was not part of the current intelligence picture. There was no prior intelligence of his intent or the plot."
Mrs May added it was still believed he had acted alone and continued: "The police have no reason to believe there are imminent further attacks (plans) on the public."
In her statement, Mrs May praised the exceptional bravery of police officers saying: "Yesterday we saw the worst of humanity we will remember the best."
Her comments came after armed police stormed houses in London and Birmingham in a series of raids after the terror attack that brought carnage to the heart off Westminster.
Eight people were arrested in the fast moving counter terror operation raids into the worst atrocity in the UK since the 2005 London bombings.
According to a source the victims of yesterday's attack were from 11 different countries, Mrs May said.
Today police said casualty figures were not as high as first feared saying four people were confirmed dead, including Pc Keith Palmer, an officer guarding Westminster Palace, and the lone terrorist
Along with 12 Britons, the victims were 3 French children, 2 Romanians, 4 South Kioreans ,1 German, 1 Pole (Poland) ,1 Chinese, 1 Irish, 1 Italian ,1 American and 2 Greeks. Also three police officers were injured as they returned from commendation ceremony and Mrs May told MPs two of them remained in a serious condition.
Two pedestrians were also killed when the attacker mowed down tourists and workers with4x4 Hyundai car in Westminister Bridge before crashing into railings in front of the Parliament.
The maniac clutched two knives, was shot dead by the armed police after he burst through the gates to the Palace of Westminister, stabbing Pc Palmer, one of several anarmed officers guarding the entrance.