A drug dealer has been jailed for life for stabbing to death a “much-loved son and brother” when he intervened to protect his friend.

Osman Musa Mohamed, 20, from Woolwich, was today sentenced at the Old Bailey to a minimum prison term of 22 years for the murder of Ahmed Ahmed in Plumstead on August 10, 2015.

The victim was knifed a number of times in the leg outside the block of flats where he lived. Police believe he was set upon at Turton House on Barnfield Road as he stepped in to prevent a group of men from attacking a friend.

His sister saw the masked mob approaching but ducked out of sight before the killers struck, the court heard. Today in a statement, Ahmed’s family said they were “heartbroken and traumatised”.

“He had his whole life ahead of him,” relatives said. “We loved him so much, the pain will never go away and we will never be the same again."

Ahmed’s partner added: "I was Ahmed's girlfriend and we were planning our future together. Two days before he was killed Ahmed proposed to me.

“I later found out I was pregnant with Ahmed's child but then suffered a miscarriage. I am now living alone in the flat we chose together. This has changed my life forever.”

Detective Chief Inspector Rebecca Reeves, of the Met's Homicide and Major Crime Command, said: "Ahmed was set upon just metres from his front door by a group of men who had clearly gone there to commit violence.

"It only took a few seconds to inflict the injuries that resulted in Ahmed's death. In that brief moment, they robbed a family of a much-loved son and brother.

“One of Ahmed's sisters found him lying in the doorway, something she will have to live with for the rest of her life."

She added: "The defendant was involved in drug dealing, and the group had gone to the flats to attack another man. It appears that Ahmed died as he tried to prevent this from happening.”

Officers continue to investigate the killing and have appealed specifically for information regarding the whereabouts of Ismail Saleban, 22, who they fear may have left the country for Denmark.

Five other men were acquitted of involvement in Mr Ahmed’s murder.

Hussein Roble, 18 (25.05.97) from Woolwich, and a 20-year-old man who cannot be named for legal reasons were cleared.

Sazzad Khan, 20, of no fixed address, was acquitted of murder but sentenced to six months in prison on February 17 for breach of an ASBO.

The case against Khalid Hashi and Hamza Dodi, 24, (12.10.91), both from Woolwich, was discontinued on 22 February.