Chilling footage of the men was captured in a new Channel 4 documentary

Shamsuddin said he was a Bake Off fan but claimed winner Nadiya was not a real Muslim

The pair giggled and Haleema said, 'That's a HD quality bruv'

Two henchmen of the ISIS militant branded ‘Jihadi Sid’ have been caught on camera laughing as they watched men being murdered in a gruesome propaganda video while they ate in a London restaurant.

Benefits claimant Mohammed Shamsuddin and London bus driver Abu Haleema, who now run the Islamist group formerly fronted by Abu Rumaysah, giggled as they watched the footage of men having their heads blown off and being drowned in a swimming pool.

Shamsuddin exclaimed, ‘The guy is foaming at his mouth, you know what I mean. Wow,' while Haleema added: ‘That’s a HD quality bruv, 4k.’

Londoner Abu Rumaysah, 32, is suspected of being the masked fanatic waving a pistol at the camera in a gruesome IS propaganda video showing the murder of five men released this month.

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Gruesome: Abu Rumaysah's friends Mohammed Shamsuddin, right, and Abu Haleema were filmed watching ISIS propaganda videos in a London restaurant

Militant: Abu Rumaysah, pictured with a jihadist flag, claimed that Britain would be taken over by ISIS

His two associates, who continue to preach and recruit in the UK, told a Channel 4 documentary that his ‘legacy lives on’ here as they boasted that they are ‘brainwashing’ youngsters with their ‘deadly’ message.

Asked for their reaction to the video while they ate at a restaurant in Harrow, North-West London, Haleema said: 'It's a deterrent, innit. If a spy knows he's going to die like that, the worst way of dying, he's not going to want to do it.'

Shamsuddin laughed at the footage but also called it 'horrific', adding: 'It's a horrible way to die, there's no disputing that.'

Despite his extreme views, Shamsuddin also admitted he was a fan of The Great British Bake Off - but added that he did not regard Nadiya Hussain, the most recent winner, to be a real Muslim.

Before escaping to the Middle East while on bail two years ago, Rumaysah - a former bouncy castle salesman - was filmed denouncing the Queen and declaring that only Muslims should hold power in Britain.

The extremist, who was born a Hindu named Siddhartha Dhar, was filmed at the start of 2014 in his messy lockup in Walthamstow, North London, which is strewn with IS paraphernalia and flags.

He said: ‘One day when the Shariah comes, you will see this black flag everywhere…

‘If you look at the way that society is moving on right now, you can see that it’s a very real, real possibility, the way Muslims are coming forward in this country.’

Friends: Mohammed Shamsuddin, left, and Abu Haleema, right, are now running Rumaysah's group in the UK

Warning: The jihadist claimed that the British population was 'living in ignorance'

Rumaysah, believed to be an associate of one of Lee Rigby’s killers, added: ‘We don’t believe in sovereignty for the Queen, we don’t believe that authority should be in the hands of the non-Muslims.

‘The public in this country are living in ignorance. Their country is involved in war.

Chilling: Rumaysah is believed to be the man featured in this ISIS propaganda video released early this month

‘And if they choose to remain silent and have this indifferent approach, then it is not going to help them.

‘One man died, in Woolwich, Lee Rigby, and the whole country went up in uproar, there are many Lee Rigbys in Muslim countries.

‘And if these issues aren’t addresses we can expect more carnage in this country and more cycle of violence.’

A few months after being filmed in 2014, Rumaysah escaped the UK with his wife and four children after being bailed for terror offences.

He later posted a picture online of him holding his baby while waving an AK-47.

Abu Haleema, who has taken over Rumaysah's group in the UK, was previously accused of radicalising a schoolboy convicted of Remembrance Day beheading plot last year, and admitted in the documentary that he was in daily contact with the 14-year-old.

He also described his plans to emulate IS executions in the UK by having homosexuals ‘chucked off high buildings’ and adulterers stoned to death in a public square in Ealing, West London.

He said large crowds would likely come out to watch the barbaric executions, explaining ‘people like that kind of stuff innit.’

Haleema also blamed the Paris attacks on the French people, claiming: ‘The chickens have come home to roost isn’t it, so it’s something they brought upon themselves.

‘This is what happens in war isn’t it, obviously we don’t condone the killing of innocents, but this is what happens in war.’

Haleema repeatedly posts internet videos denouncing British values which have won him a large following. He has previously worked as a bus driver, although it is not known if he still does so.

Home: Abu Rumaysah, born Siddhartha Dhar, lived in Walthamstow before he travelled to Syria for jihad

Family: He posed for a photograph with his young baby after arriving in Syria to live with ISIS

He said: ‘What I’m saying in my videos, this is the basic message of Islam, and the aim of these videos is to radicalise people.

‘It’s to brainwash people, to clean their brain of the filth of the kuffar [non-believers]. And obviously if ISIS is calling to the same thing then that’s just a coincidence.’

Shamsuddin admitted: ‘Our message is deadly, we are calling for world domination, and for Shariah for the UK, and for that alone, our message is quite deadly.’

The 39-year-old father of five was brought up in North London by his Indian parents - his father was a restaurant chef - and studied at Southampton Solent University.

Shamsuddin is said to have developed extremist views after he invited radical cleric Omar Bakri Mohammed to speak at the university's Islamic society, of which he was the head.

Fan: Shamsuddin said he watched The Great British Bake Off but thought that winner Nadiya Hussain was not a real Muslim

In September 2014, he was arrested on suspicion of encouraging terrorism and being a member of a banned group, but he was never charged.

Haleema was last year banned from using Twitter and previously had his passport confiscated over fears he could travel to Syria, although he insisted he had done nothing wrong.

His name came up in an unrelated terror trial recently, when a court heard that he had been unable to help another extremist make a video because he had to go to his local job centre.

Director Jamie Roberts said he had 'chills' when he heard Rumaysah’s voice in the recent IS propaganda video.

After the video came out, he received a text from Shamsuddin with a link and the message: 'You may know the voice.'

Mr Roberts said he thought much of Rumaysah's rhetoric was 'fantasy', adding: 'The black flag over Downing Street - I don't believe that's ever going to happen but someone might try and do it.'