The family of a man brutally killed in an axe attack are still no closer to understanding the motive behind his murder, despite the conviction of those responsible.

The younger brother of Thirukumar Sothilingam, who died in October last year, said he was upset the gang responsible for his death refused to explain why they killed him and denied murdering him in court.

Thavakumar Sothilingam, 26, said his older brother, from Dennett Road, Croydon, had looked after him and the rest of his family since moving to the borough 10 years ago.

He said: "I lost my brother that's the main thing, but we still don't know the reason why. They didn't ever give us one, not even in court.

"That's what is so upsetting. All this time and we still don't know the reason."

He added: "He looked after us all. He was the oldest, and he took care of all of his family and his mum and dad back in Sri Lanka.

"He came to this country 14 years ago and he helped me when I moved here. He helped explain how things worked. I'm not sure who is going to look after us now."

Thirukumar's parents travelled from Sri Lanka to see four men sentenced to life imprisonment at the Old Bailey last Wednesday after being found guilty of murder and criminal damage.

Shanthan Tharamalingam, 32, of Blackbourne Lane, Tottenham, Sugandthan Nadarajah, 25, of Orchard Close, Woking, had denied murder and a count of criminal damage. While Sasikaran Selvaratnam, 23, of no fixed address and Ranjan Shanmugha-nathan, 27, of Kingston Avenue, North Cheam, denied murder but admitted the charge of criminal damage.

The court heard how the four men attacked Mr Sothilingam's Vauxhall Corsa after seeing it parked near the Flaming Grill kebab house in London Road, West Croydon, in the early hours of October 28 last year.

When he returned to his vehicle the gang struck Mr Sothilingam four times with an axe and left him lying on the pavement in a pool of blood. He suffered severe head injuries.

He died 12 hours later after being transferred from Mayday Hospital to Charing Cross Hospital.

Police arrested the four men within half an hour of the attack.

In court Sir Allan Green QC, prosecuting, said the attack was carried out in revenge for a car accident Nadarajah had been involved in a year earlier.

But investigating officer Detective Inspector David Morgan, of the Lewisham-based specialist crime directorate, told the Guardian the men had never given an indication of a motive to police.

He said: "This is a good result for the family and for the police investigation which put so much work into preparing the evidence necessary to secure a conviction.

"The level of violence used in this crime was horrendous and this verdict was exactly what the family and police were hoping for."

Judge Anthony Morris said all four men should serve a minimum of 14 years.