A Muslim exorcist stabbed to death in east London may have been killed because of his work, a colleague claimed today.

Father-of-three Zakariyya Islam, 46, who specialises in expelling demons by reading from the Koran was killed at his 'black magic' healing centre last night.

The healer had worked as a exorcist for around 20 years and founded the Ruqya Therapy Centre, based on a side street close to the East London Mosque in Whitechapel.

He treated people who believed they were possessed by evil spirits, also known as 'jinns.'

Police guard the scene where faith healer Zakariyya Islam was stabbed to death yesterday

Police and paramedics rushed to the centre just after 6.30pm yesterday where he was found with critical injuries to his torso but despite desperate attempts to save his life he was pronounced dead at the scene.

A 43-year old man known to Mr Islam was arrested on suspicion of murder and is set to be questioned by police after being taken to a hospital with hand injuries.

Colleague Tasawer Islam, 51, said he received the news by phone at 11pm yesterday evening and believes he may have been killed due to his work.

He said: 'It was the last thing I expected to hear. I am lost for words that something like this could happen to him.

'We do have enemies in this field because there are a lot of people who don't like our work. They don't like us assisting people. There are people causing problems and we give advice.

'This is what we do to keep people safe and when we perform those actions, the persons who are attacking - their powers are weakened. Even I get threatening messages when I help people who ask for advice.

'There are certainly people out there. In my opinion that's what has led to this. I don't believe he had any personal issues that could have caused this.'

Forensic officers at the scene. A colleague has suggested Mr Islam was killed due to his work as a healer

Tasawer Islam added: 'The only person that I can think would have something against him is someone to do with his work.

'It will be someone who controls these powers 'Jinns'. They have to go through a lot of effort to attack someone with Jinns and if he has exorcised someone then they have to go through all the trouble again.

'They appear ordinary on the street but in the darkness of night that's what they do.'

The centre, which is part of an office block on Greatorex Street and was sealed off by police for forensic searches, also offers advice on black magic sorcery, witchcraft and 'evil eye'.

Describing his work, Tasawer Islam, who offers similar treatments over Skype and joined the business five years ago, said: 'It's something similar to what you would call clairvoyance. We recite directly from the Koran and it's the words that are very soothing.

'Everything that is damaging around you gets destroyed but lots of people don't believe or they don't understand.

'People with mental health issues - all we have to do is speak to them - not even physical contact - we just say the words. It's like yoga - we do the recitations from the Koran for about 30-40minutes and people feel better.

'You can be inhabited or posses by these powers - everything around you feels bad. You feel miserable and you want to sleep all the time.

'A doctor will just tell you that you need to sleep it off but by listening to the Koran you can get rid of it all. It is using the Koran to exorcise those spirits.'

Police believe the suspect was known to the victim. They have arrested a man on suspicion of murder

He said Zakariyya Islam was was born in Bangladesh but grew up in the UK. He lived in Mile End and had recently hosted the wedding of one of his daughters

Last year he hosted a conference on 'The World of Jinns' at the East London Mosque which he visited regularly and also practised 'cupping' or 'hijama' - an ancient Chinese tradition of placing cups on a person to create a vacuum.

The former caretaker at Stepney Green Secondary School and former cab driver was also a member of Islamic Forum of Europe.

Paying tribute to his friend, Tasawer Islam said: 'He was a very gentle and charitable person who would help anybody.

'He was in the business of helping people who were a bit unstable in their lives. He was the sort of person who would go around and out of his way to help people.

'It's a huge shock for me. The community will definitely be worse off without him.'

The killing took place on at the centre which is on a side street in Whitechapel near the East London Mosque

A spokesperson from Scotland Yard said: 'Police were called by London Ambulance Service to an address in Greatorex Street, E1 at 18:38hrs on Monday, 14 September following reports of a stabbing.

'Officers and London Air Ambulance attended and found a man aged in his forties suffering from critical stab injuries to the upper body. He died at the scene a short while later.

'A 43-year-old man has been arrested on suspicion of murder. He has been taken to hospital for the treatment of a hand injury. He will subsequently be taken to an east London police station for questioning.

'A knife has been recovered near the scene. At this early stage it is believed that the victim and suspect were known to each other.