Two men have been interviewed under caution in relation to last year's fatal Stanley Road gas explosion.
The pair voluntarily attended attended Wembley Police Station on Thursday last week to assist detectives from the Putney-based homicide and serious crime directorate who are investigating.
Neither interviewee was arrested, police stressed.
Emmad Qureshi, 26, was killed by a wound to the neck in the blast on May 7, 2008 that destroyed three houses and left two others injured and numerous families temporarily homeless.
Since the criminal investigation is ongoing, the inquest into Mr Qureshi's death is still adjourned to an unspecified date.
There have been no arrests or charges so far although the detectives involved recently received back from the Health and Safety Executive laboratories the results of tests carried out on pipes and gas equipment removed from the blown up house.