Detectives are keen to trace three men seen loitering in the area before a man was stabbed at a property in Roehampton.
The victim, believed to be in his late 30s, was found with serious injuries, following a break-in at the house, on Tuesday evening.
A 15-year-old boy has been remanded in custody after appearing in court today, charged with murder, and a 17-year-old male is being questioned by police.
Anyone with information should call police on 0208 721 4205 or Crimestoppers on 0800 555 111.
More top news
Police are appealing for information after a well known DJ was shot five years ago in north London.
More than 100 firefighters battled for five hours to bring a huge warehouse fire under control.
A 7-metre high sculpture has been installed in the shadow of the Gherkin building, as part of this year's Sculpture in the City exhibition.