A £20,000 reward for information has been posted one year after an Upper Norwood couple were gunned down in their home.

Jordan Jackson, 20, and his girlfriend of almost five years, Leyla Djemal-Northcott, 21, were murdered when two masked gunmen stormed into their Menlo Gardens flat.

Jordan was shot in the neck and died in the hallway. Leyla was shot once in the head as she lay in bed.

Jordan's twin brother Kieran survived, despite being ordered to put his hands on the back of his head before being shot from behind.

But he lost several fingers and sustained a serious head injury. His girlfriend, who was also there, escaped uninjured.

Leyla and Jordan were childhood sweethearts who moved into their flat in December 2005. Despite a high-profile investigation and the best efforts of detectives, their killers remain at large.

Police officers handed out leaflets at Menlo Gardens in Beulah Hill, between 6am and 7am this morning on the first anniversary of the murders.

They want to trace a number of people and vehicles seen in the area during the gun attack. An appeal for anyone in the vicinity of Menlo Gardens between 6am and 6.50am that day to come forward has also been renewed.

Police want to trace three black men seen leaving the block of flats and getting into a saloon car parked in Elizabeth Way, the drivers of a blue coloured estate car and a BMW estate car seen to leave the car park of the estate at the time of the shootings and a black male who was seen loitering inside the block by the exit.

Leading the case for the Met's Operation Trident, Detective Chief Inspector Peter Valentine, said: "I again appeal to anybody who has information which will assist the enquiry to come forward and speak to the enquiry team. All information will be treated in the strictest of confidence.

"Two young people in the prime of their life were brutally murdered and one other was left maimed for life. The level of violence used on this day has no place in our society and I would encourage anyone who has anything, no matter how small, to make contact."

One of the gunmen is described as a dark-skinned black man, around 6ft and was wearing dark clothing.

His accomplice was described as a lighter-skinned black man, between 5ft 4in and 5ft 5in, wearing dark clothing.

Police said two men matching the description of the suspects were seen in the vicinity of Menlo Gardens shortly before the attack took place.

The reward is offered to those who provide information leading to the conviction of the killers.

Anyone with information should call the incident room on 020 8247 4553 or Crimestoppers anonymously on 0800 555 111.