It has been one week since the fatal stabbing of Lewis Elwin in a Tooting residential street.

Mr Elwin, 20, was knifed in Penwortham Road at about 3.30pm on Monday, April 18, and staggered toward Thrale Road before collapsing. 

A murder investigation was launched by the Metropolitan Police but no arrests have been made.

April 22: Lewis Elwin murder: woman used jumper to stem bleeding in last moments of 20-year-old's life

April 20: Tooting murder victim Lewis Elwin died from "a stab wound to the chest"

April 19: "Things like this don't happen round here": Neighbourhood in shock after murder of Lewis Elwin in Tooting​

The independent charity Crimestoppers is offering a reward of up to £10,000 for information leading to the conviction of those responsible for Mr Elwin's murder.

Detectives will be returning to the scene in Tooting today, April 25, to appeal for information.

Officers from the Homicide and Major Crime Command will be joined by uniformed colleagues from Wandsworth borough while they hand out appeal leaflets and speak to members of the public.

Detective Chief Inspector Diane Tudway, leading the investigation, said: "I am of the belief that Lewis had already been stabbed when he was seen jogging along Penwortham Road.

"I continue to retain an open mind as to the motive behind the murder. There are a number of lines of enquiry ongoing to establish the circumstances of the incident and I am very keen to understand what took place between 3.36pm and 3.40pm.

"We have spoken to a number of local people but have limited information about the events of that day. I am appealing to anyone who is yet to come forward to do so with the confidence that they will be treated with the utmost sensitivity.

"It is important that we build as clear a picture as we can, so that we can establish who attacked Lewis and what the motive may have been. We also need to find the murder weapon and identify where the attacker went immediately after the incident.

"I am aware there has been speculation within the community as to the motive behind the murder, and this is understandable. But we need witnesses to tell us what they themselves know about what happened to Lewis.

"Moyser Road is a busy residential road and runs between Mitcham Lane and Furzedown Drive, and I am confident more people would have seen or heard something."

On the day he died, Mr Elwin was wearing a black jacket with a fur lined hood, blue jeans and black Nike trainers with silver spots.

He was carrying a black bag with a Nike logo and a long shoulder strap.

His family has joined the appeal for information about the stabbing.

In a statement, they said: "Words can't describe the pain and loss we feel. We are still in shock. We pray that this doesn't happen to your son, your brother, your family.

"But if our community continue to stay silent then Lewis's senseless murder would have been for nothing. Now is the time to come together and unite in our fight against knife crime; and the epidemic of murders plaguing our young men.

"Someone knows what happened to Lewis."

Information can be sent anonymously to Crimestoppers by calling 0800 555 111 or filling in the anonymous online form at crimestoppers-uk.org.