Controversial preacher Anjem Choudary claims to know one of the Woolwich attack suspects, it has been reported.
Choudary, former leader of the banned banned Al Muhajiroun group, told The Independent he knew one of the men, who was known as Mujahid.
He told the paper: “He was a pleasant, quiet guy. He reverted to Islam in about 2003. He was just a completely normal guy.
"He was interested in Islam, in memorising the Koran. He disappeared about two years ago. I don’t know what influences he has been under since then.”
It came as the killers were reported to be of Nigerian background.
The men, who are being treated in separate hospitals while under arrest, are most likely to be British citizens converted to a radical form of Islam, the Press Association reported.
They are not thought to have links to terror groups based in Nigeria, such as the jihadist militant organisation Boko Haram.
The Foreign Office warns of a high threat from terrorism in the West African nation and raises the prospect of a risk of retaliatory attacks following the French intervention in Mali.
Boko Haram is the most prominent terrorist threat in Nigeria. The group's extremists aspire to establish Islamic law in Nigeria and carry out attacks across states mainly in the north.
In 2011, Boko Haram claimed responsibility for the bombing of the UN building in the Nigerian capital of Abuja, which killed 23 people in an act that showed the group could target Western interests.
The group, whose name means ''Western education is sacrilege'', was blamed for nearly 800 killings last year alone.