A £20,000 reward has been offered to catch the killers of Mark Corcoran, who was stabbed to death on Valentine’s Day this year.

His heartbroken family also plan to flood Croydon town centre with leaflets this Saturday in an attempt to help track down the 26-year-old’s murderers.

Mr Corcoran’s step-father Alan Smith said the family had been torn apart since the murder in Whitehorse Lane, Selhurst six months ago.

He said: “My wife’s been devastated by this, all our lives have.

“All mothers are extremely close to their sons but they were more like brother and sister –- they were on the Playstation together and were just like friends really.

“It’s absolutely destroyed her and she will never be the same.”

Mr Smith, 60, revealed the family had been spurred into action as days turned into months since his step-son’s murder without anyone being charged.

He said: "It’s six months down the line and it’s still hard to absorb.

"We don’t feel any closer to this being over, and all the time someone who’s committed this crime is out there free to do it again to someone else.

"We’ve sat at home for months now and left it to the police, and now we’re going to get out there and try to do our best."

Mr Smith revealed he and his wife tried to stop Mr Corcoran going out on the day he was killed as he was starting a new job the next morning.

The builder managed to stumble into Subitha Food and Wine begging for help after being stabbed through the liver with a nine-inch knife.

Forensic teams have struggled to make any headway after finding a dozen knives down a single manhole near the murder.

Detective Chief Inspector Cliff Lyons, of the Homicide and Serious Crime Command, said: “We still do not know why Mark was stabbed that night.

“He was wearing a distinctive black and white stripy top and would have struggled to walk the 100 yards to the shop.

“Lots of people were around that evening, either out celebrating Valentine’s Day or at the football match. We would like to hear from these people no matter how insignificant their information may seem, it may assist us with finding out what happened to Mark.”

Anyone with information can call the incident room on 020 8721 4961, or Crimestoppers anonymously on 0800 555 111.