The man, who is only known as Mohammed, sprang into action when he saw the Islamist extremist wielding two knives in either hand during his lunch break, according to the Sun Online.
He joined a group of men, including a Polish chef named Lukasz, who helped disarm Khan after he had killed two people and injured three others on Friday.
Footage posted online showed Khan being taken to the ground as one man sprayed him with a fire extinguisher and another, Lukasz, lunged towards him with a narwhal tusk.
Mohammed was apparently filmed in one of the videos and is said to have been interviewed by officers before he went back to work.
Tour guides Thomas Gray, 24, and Stevie Hurst, also helped to stop Khan when they saw him from their car.
Khan, who was also wearing a fake suicide vest, was shot dead by police on London Bridge.
Mohammed’s boss said: ‘He was there. He held the guy down.
‘The terrorist was pinned down to the floor.
‘He was on his break. He came back afterwards to work.
‘He didn’t say anything. He went back to work. He was washing dishes.’
An urgent review of terrorists released from prison has been launched in the wake of the knife attack by Khan, who was freed halfway through a 16-year jail sentence.
He was on licence and wearing an electronic monitoring tag when he attended a conference on prisoner rehabilitation hosted by Cambridge University scheme Learning Together at Fishmongers’ Hall near London Bridge.
The attack has prompted the Ministry of Justice to review the licence conditions of every convicted terrorist released from prison, which is understood to be around 70 people.
Khan was part of an al Qaida-inspired terror group – linked to radical preacher Anjem Choudary – that plotted to bomb the London Stock Exchange and build a terrorist training camp in Kashmir.
Cambridge University graduate Jack Merritt, 25, was named as the first victim of the knife rampage.
He helped organise the conference where the attack began.
Details of the second female victim have not been released.
Everyone has the right to make his own decisions, but none has the right to force his decision on others.