People who knew the jihadists who struck Saturday with long knives against defenseless London diners saw something, and they said something. But the British government did nothing.

In fact, one of the three attackers was reported to authorities for following the teachings of a known radical sheik based in Dearborn, Michigan.

Dearborn is home to the largest Arab-American community in the U.S.

According to the London Telegraph, a former friend of one of the three dead London suspects claimed one of the attackers had been radicalized while watching Dearborn cleric Ahmad Musa Jibril’s YouTube videos, and he said he contacted authorities after becoming concerned about his friend’s Islamist views.

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The Telegraph described the Dearborn sheik as "infamous American hate preacher Ahmad Musa Jibril."

The former friend of the London jihadist said: "We spoke about a particular attack that happened and, like most radicals, he had a justification for anything and everything. And that day, I realized I needed to contact the authorities.”

He added: “He used to listen to a lot of Musa Jibril. I have heard some of this stuff, and it's very radical. I am surprised this stuff is still on YouTube and is easily accessible. I phoned the anti-terror hotline. I spoke to the gentleman. I told him about our conversation and why I think he was radicalized."

The suspected attacker was not arrested and was allowed to keep his passport.

"I did my bit, I know a lot of other people did their bit, but the authorities did not do their bit," the friend said.

The former friend, who was not identified at the request of police, told the BBC he contacted police after comments the man made about previous attacks by other jihadists. But, according to the Telegraph, he said the authorities took no action "despite evidence of increasingly extremist views."

On his website, Jubril, 46, has a smattering of teaching videos and invites non-Muslims to convert to Islam.

In one video, he teaches that Muslims will not achieve success unless the entire ummah (global Muslim community) is united in obeying Allah's commands for Shariah law.

"Look at the submission to Allah on this earth, the Shariah of Allah in this earth, how it's implemented and in accordance to that, the victory comes from the heavens. Simple, simple and clear. We never achieve victory through power in numbers, never. We will always achieve our victories and success through Allah."

Watch video teaching from Sheik Ahmad Musa Jubril of Dearborn:

In the above video, the "enemy" is clearly presented as the non-Muslim world, which Jubril refers to as "the lowest people."

A 2014 report by the London-based International Center of the Study for Radicalization and Political Violence described Jibril, a Palestinian-American cleric born in Dearborn and another Western-based cleric, Musa Cerantonio, as "important figures whose political, moral and spiritual messages are considered attractive to a number of foreign fighters." The terrorists followed the two imams on social media.

"Their popularity is also reflected on Twitter, where they are followed by 60 and 23 percent of foreign fighters, respectively, and is particularly strong among groups like ISIS, whose members provide a majority of their likes and follows.”

Amazingly, the London-based center's report concluded, “None of this should suggest that either individual is a member of ISIS or Jabhat al-Nusrah, nor should it be taken as indicating that they are involved in facilitating the recruitment of foreign fighters.”

The Detroit News reports that in 2005, Ahmad Jibril and his father, Musa Abdallah Jibril, 66, were convicted on 42 counts of an indictment charging them with bank fraud, conspiracy, money laundering and other counts. Ahmad Jibril was sentenced to five years and 10 months in prison; his father was sentenced to four years and 10 months. Federal authorities accused the Jibrils of buying 13 homes and two apartment buildings in the Detroit area since 1988 and insuring them for far more than they were worth.

Criminal background

The father-and-son team were accused of defrauding six local banks of more than $250,000.

The government entered into the court record a "Supplemental Sentencing Memorandum" that stated that a family photo album seized during the investigation contained "photos of Ahmad as a teenager dressed as a mujahid … (and) photos of very young children holding apparently real firearms, 'playing' at holding each other hostage and aiming the weapons at each other’s heads," according to the report by International Center of the Study for Radicalization and Political Violence.

The memorandum also revealed that Ahmad Musa Jibril was running a Salafi website (AlSalayfoon.com) at the time of his arrest that "contained a library of fanatically anti-American sermons by militant Islamic clerics, in English and in Arabic."

In March 2015, a federal judge in Detroit ordered Jibril to testify about his finances, days before his supervised probation was set to expire.

During a hearing in U.S. District Court, Chief Judge Gerald Rosen ordered Jibril to testify under oath about the source of his income. Jibril cited his Fifth Amendment right against self-incrimination and remained silent.

During the 2015 court proceedings, Jibril’s attorney, Rita Chastang, said, "There is no evidence he is hiding assets."

The Saturday assault unfolded when a rented van veered off the road and barreled into pedestrians on busy London Bridge. Three men then got out of the vehicle with large knives and attacked people at bars and restaurants in nearby Borough Market until the attackers were shot dead by police.

'This is for Allah'

"They went, 'This is for Allah,' and they had a woman on the floor. They were stabbing her," witness Gerard Vowls said.

Florin Morariu, a Romanian chef who works in the Bread Ahead bakery, said he saw people running and some fainting. Then two people approached another person and "began to stick the knife in … and then I froze and I didn’t know what to do."

He said he managed to get near one attacker and "hit him around the head" with a bread basket.

"There was a car with a loudspeaker saying 'go, go' and they (police) threw a grenade. … and then I ran," he said.

London police said officers killed the three jihadists within eight minutes of arriving at the scene. Eight officers fired some 50 rounds, said Assistant Commissioner Mark Rowley.

ISIS claimed responsibility for the attack.