Abdul Samad, 25, was hacked to death with knives and meat cleavers after responding to a bogus fast-food order which gave the fashionable Islington address of Lord Falconer, the Solicitor General and close friend of Tony Blair.
At a press conference at Scotland Yard yesterday, Detective Superintendent Colin Hardingham said he could not discount the possibility that the attack was linked to a "curry war".
"This murder didn't happen by accident, it was planned," he said. "I'm confident that the people knew him and that Abdul Samad knew the people and those that planned it.
"He was most viciously attacked. It was a brutal attack. In fact I would go so far as to say it was an execution."
Det Supt Hardingham said he had ruled out robbery as a motive for the crime, which he believed had been planned over many days or even weeks.
He revealed that a similar hoax call to the Curry-in-a-Hurry takeaway, where Mr Samad was the only night-time delivery driver, had been made for the same street only two nights before the attack.
The call could have been a practice run, or the attackers may have been confused because Mr Samad had arrived in a different car before taking the meal back to the shop.
Det Supt Hardingham said that Alwyne Road in Islington had probably been chosen for the attack because it was a quiet street. Lord Falconer and his family have been interviewed by detectives and said that they had never ordered such food.
Police believe their house was picked because its wide drive made it likely that the delivery car would pull up right outside, making the attack easier to carry out.
In the event, Mr Samad briefly escaped his attackers and ran 200 yards into nearby Alwyne Villas, where he was attacked opposite the former home of Dame Stella Rimington, the former head of MI5. He was repeatedly stabbed and hit with what police believe was a baseball bat and died three hours later in hospital, early on 22 May.
An internal police inquiry is under way into how officers who arrived at the scene believed the victim to have been white. The error, which may have been due to his massive loss of blood, set in chain a series of events which led to the arrest of Mr Samad's brother and cousin, who were traced from leaflets found in the victim's possession.
Det Supt Hardingham admitted that the mistake had led to "six or seven hours of confusion". Mr Samad's relatives are not suspected of being involved in the attack.
Mr Samad had recently bought a part share in the takeaway business, which was in St Paul's Road, Islington, a short distance from where he was attacked.
The dead man's sister, Halima Begum, 23, yesterday made a tearful plea for help in apprehending the killers, who witnesses have described as being Asian men in their twenties.
She said the family had been shocked by the brutality and personal nature of the attack.
"What we have to get clear is that my brother is 25," she said. "Whatever he may have done to whoever, the brutality of this murder does not fit ... whatever he may have been involved in is far too petty for this murder. It just does not make sense."
Some members of the public have suggested to detectives that the motive may have something to do with Mr Samad's personal life. He was married with two daughters, aged one and three, and came from a close-knit family of six children.
Police are particularly keen to obtain further information from the Bangladeshi community in and around Brick Lane in east London.
They have offered protection to any potential witnesses who may fear reprisals, and an incident room can be contacted by phone on 0181 358 1336.