Police have arrested a second man as part of their murder investigation in Hillingdon.
A 30-year-old was arrested at around 8pm last night (Thursday, September 18). He is being held in custody at a west London police station.
A 42-year-old man died at a residential address in Ryefield Avenue, Hillingdon, yesterday.
It was announced this morning (Friday, September 19) that his death is being treated as murder.
The death came just two days after two boys were stabbed and injured in Mulberry Parade, West Drayton, which has led to one arrest so far.
In the Hillingdon incident, police officers called at 12.53pm to reports of an assault discovered the victim unconscious and being treated by London Ambulance Service staff.
Read the earlier story: Man dies and another arrested after assault in Hillingdon
The victim died at the scene around 2.10pm.
A man, aged in his 50s, was arrested in connection with the assault and was taken to a west London police station yesterday afternoon.
A post-mortem examination of the victim is due to be held at around 2pm today at Uxbridge Mortuary.
Although the formal cause of death is not yet known, police confirmed the man did not suffer from stab wounds.
The man's next of kin have been informed although formal identification has not taken place.
An incident room opened under Detective Chief Inspector Neale Baldock of the Homicide and Major Crime Command.
Anyone with information is asked to contact the incident room on 020 8345 1572 or Crimestoppers anonymously on 0800 555 111.