A year after a young Tamil father was brutally stabbed to death, police admit they are no closer to finding his killer.

No one has been convicted of murdering Akilankumar Kanthamsamy, 28, knifed in the heart outside a baby’s first birthday party at the New Horizon Centre, Pollards Hill on October 22, 2011.

Police believe he was killed after accidentally walking into a street fight between young people arguing over money and stolen cannabis.

Dwayne Roberts, 18, of Mitcham Lane, Streatham, was acquitted of the murder after a trial at the Old Bailey in May.

During the trial a key witness refused to take to the stand, and police have admitted there is no new evidence to reopen the case.

Don Anthony, Mr Kanthasamy’s neighbour, said it was a “tragic shame” his widow, Parmita, has not seen justice done.

He said: “I spoke to his wife after the murder and she was so, so upset. She is a very sweet and innocent woman and I know her husband would never hurt anyone.

“This is an injustice, a really bad injustice. We still talk about what happened to him and it’s horrible to know the killer is out there somewhere.”

A second friend, Baskaran Sinnathurai, described the night the father-of-one died.

He said: “He came in and was speaking very softly [in Tamil]. He said that someone had got him with a knife then he just dropped to the floor, like it was slow motion.

“There was so much blood, so much blood. We were trying to shake him, but it was no good.”

A tree has been planted outside the New Horizons Centre in Mr Kanthasamy’s memory and a plaque will be installed soon.

Meetings held in the aftermath revealed deep concerns from residents on the estate about the problems of gangs, drug dealing, insufficient lighting, and a general lack of police.

Naomi Martin, director of the Commonside Community Development Trust, at the New Horizon Centre, said the number of security cameras had increased from 16 to 22 covering the full perimeter of the site.

She said: “Lighting around the centre has been improved. That was dealt with really quickly because we knew it needed to be done.”

Darren Williams, Merton police’s borough commander, said: “Merton is one of the lowest crime boroughs in London and incidents of that nature are reasonably rare.

"That was an isolated incident involving a group of males that was spontaneous and not planned – I don’t think it happened because it was Pollards Hill.”

It is understood that all unsolved murders in London are reviewed by the Metropolitan Police every two years, but an investigation into Mr Kanthasamy’s murder cannot be reopened without new evidence.

A Met spokeswoman said: “This case has been through the criminal justice system and a jury acquitted Dwayne Roberts at the Old Bailey.”

Anyone with information should call the Met’s incident room on 020 8721 4906; or anonymously to Crimestoppers on 0800 555 111.