The trial of four Asian men accused of the horrific gang murder of two brothers in Tooting collapsed at the Old Bailey today.

Tooting MP Sadiq Khan said the news would leave the local Muslim community "devastated".

Quadeer Khan, 23, of Garratt Lane, Tooting, Bilal Kayani, 20, and Shahzad Kayani, 19, both of Gatton Road, Tooting, and Omar Butt, 32, of Halford Road, Fulham, were all cleared of murder on the direction of the judge after it was revealed the two main prosecution witnesses, brothers Favard and Javard Bhatti, spoke to the victim's father, Shahid Ali, over the phone during the trial.

Judge Christopher Moss said: "I conclude there is an irresistible inference to be drawn that the additions and change to the evidence were occasioned by telephone traffic...the probity of these proceedings had been affected in such a way it can never been cured."

The prosecution appealed against the decision at the High Court but appeal judges there backed Judge Moss's decision.

Tooting MP Sadiq Khan said: "The local community has still not fully recovered from the original crime, and the news that this trial was compromised, and therefore aborted, will be devastating for those Tooting residents who simply wanted justice to be served."

Last year six men were convicted of murdering 24-year-old married dad, Mohammed Ali, and his brother Hayder, 23, a recruitment consultant in Fircroft Road, Tooting, on April 21, 2006.

That trial, at nearly eight months, was one of the longest murder trials heard at the Old Bailey, costing at least £20million.

Mohammed, an IT sales manager of Tyneham Road, Battersea, was married to wife Sadia. She was six months' pregnant at the time of his death and expecting their second child.

Hayder, a recruitment consultant who lived in Elborough Street, Southfields, was engaged and due to marry in November last year.

Their murders were related to an ongoing feud between Muslim gangs dating back to 2003.

On the night of the murder the pair were set on by up to 30 attackers. Mohammed was stabbed in the stomach, punched, kicked and struck with weapons.

Hayder was stabbed four times in the back, stabbed in the leg with a screwdriver and hit with a baseball bat, hammer and metal pole and sustained a number of head injuries including a fractured skull.

Police searches recovered 39 different weapons including two knives, four bats, three screwdrivers, a hammer, knuckle dusters, metal poles, scissors, a broken bottle and even a menu board from an Indian restaurant.

Imran Ali, 20, of Wilson Avenue, Mitcham, Noor Kayani, 22, from Gatton Road, Tooting, Imran Hussain, 23, of Selkirk Road, Tooting, Aazam Butt, 20, of Arthur House, Halford Road, Fulham, Hassan Mir, 18, of no fixed address, and Usman Butt, 19, were convicted of murder at an earlier trial and are due to be sentenced later.

Kashif Khan, 20, of Hebdon Road, Tooting, and Sultan Mir, 24, of no fixed address, were cleared by the same jury.