Two men can be seen cornering the terrorist on London Bridge armed only with the nearest objects which came to hand – a 5ft- long antique narwhal tusk and a fire extinguisher.
A third man uses just his bare fists to help force Khan on to the ground before the jihadist is shot and killed by armed officers who arrived on the scene within minutes of him launching the attack.
It is now thought the man who used the whale tusk as an impromptu weapon to corner Khan was a migrant – a Polish-born chef who had been working at Fishmongers’ Hall.
Colleagues and those attending a prisoner rehabilitation conference organised by the Institute of Criminology at Cambridge University told how with barely a thought for his own safety the chef, called Lukasz, grabbed the tusk from a wall from where it had been displayed inside the hall and attempted to defend others around him from Khan. As the fight spilled out on to London Bridge, and despite being stabbed three times by Khan, Lukasz used the tusk to prod and push him against a railing to prevent him escaping and causing further injury.
A man alongside him sprayed fire extinguisher foam over Khan to disorientate him further.
A colleague said: “Lukasz grabbed a pole and ran at him, getting stabbed in the hand, but continued to pin him down. Being stabbed didn’t stop him giving him a beating. Lukasz is a hero.”
Khan is believed to have started “lashing out” in a downstairs room of the hall but was grabbed by conference-goers and bundled out of the front door as he tried to go upstairs.
Also involved in brave attempts to pin down and disarm Khan in the moments before the armed officers arrived was an off-duty British Transport Police officer who wrestled one of Khan’s two knives from him and – holding it with care so as not to contaminate any fingerprints or DNA on the weapon – ran from the scene so it was out of reach.
Passer-by Thomas Gray (24) leapt out of his Mini and helped wrestle Khan to the pavement before stamping on his wrist to release the knife from his hand.
Mr Gray described how the attacker brandished an eight inch knife in each hand. “One thought was going through my mind – stop the dude. I’ve played rugby for most of my life and the rule on and off the pitch is ‘one in, all in’,” he told reporters. “I was just a Londoner doing my bit.
“Hats off to the six or seven guys who were there before me, they’re so brave.”
After Mr Gray attack, he went to the pub with his friend. “We had a pint and shook it off, then came back to let police know I was here with the keys for the cars in case they wanted me to move one of them.”
Another bypasser, tourist guide Steve Hurst (32), told the BBC: “I was driving, I stopped the car and ran toward it. I don’t know why.
“There were about five guys there. I jumped in and kicked him in the head to make him release his knife. He was shouting ‘get off me, get off me’.
“We wanted to make sure we got the knife away from him as quickly as possible. We wanted to kick him. Everyone was shouting. The knife flew away.”
A witness said: “One of them had a fire extinguisher, he was hitting the man with it, hitting his hand to knock the knives out of his hand. They were all grappling with him on the ground.”
Within a minute or two, firearms officers from City of London police arrived. One ran across the road and jumped over the security barrier before yelling at the men to stand clear.
“Don’t move, don’t move,” he was heard to shout. Within seconds, a shot rang out. As the bullet was fired, the suspect pulled open his jacket, revealing a suicide vest – which later turned out to be fake.
The witness added: “The moment they rolled him over off his chest, they saw he had a bomb vest. The police arrived so quickly. They told us ‘get the f**k back’. They had rifles. They put three rounds into him.”
Another eyewitness said: “The suspect was immediately sick. The police then moved right back and shot at him repeatedly from a distance. Then no one went near him for about half an hour.”
Among members of the public who chased Khan from Fishmongers’ Hall were former prisoners attending the rehabilitation event – including a man convicted of killing a young woman. James Ford (42) was out on day release when he joined those who chased Khan out on to the street before he was pinned to the ground.
Ford was jailed for life with a minimum of 15 years in 2004 for the murder of Amanda Champion, who had a mental age of 15.
It is thought Ford rushed to the scene and tried to save the life of a woman victim of Khan. Sources said his actions during the attack had probably saved lives.
But Ms Champion’s family expressed concern that Hall had been allowed on day release from prison without his victim’s relatives being informed in advance.
Ms Champion was found strangled and with her throat cut on waste ground near her home in Ashford, Kent, in July 2003.
Police had no leads in the case until a Samaritans worker broke the organisation’s strict confidentiality policy and revealed that Ford, a factory worker and amateur wrestler, had called and confessed: “I’ve killed a girl.”
Ms Champion’s family had tried to block Ford’s parole, and found out he was out on day release on Friday, only when their police liaison officer warned them his image was on TV reports of the attack. Ford was serving the final days of his sentence at an open prison in Kent, when he was allowed to attend the event.
Ms Champion’s aunt Angela Cox (65) said: “He is not a hero. He is a murderer out on day release, which us, as a family, didn’t know anything about. He murdered a disabled girl. He is not a hero, absolutely not.
“I don’t care what he’s done today, he’s a murderer.”
The spontaneous decision of civilians to fight back was part of a trend that has gathered pace since the 9/11 attacks in 2001, when passengers on United Airlines Flight 93 challenged the hijackers, causing them to crash in a rural area before they could reach their target in Washington.
Plane passengers also played a huge role in subduing shoe bomber Robert Reid before he could light a fuse sticking out from one of his shoes on a flight from Paris to Miami in December 2001. Their intervention saved roughly 200 lives.
In 2015, a man opened fire on a train on its way from Amsterdam to Paris. French, US and British passengers confronted the attacker and subdued him when his AK47 jammed.