A 16-year-old boy is being questioned in connection with the murder of a father-of-three who was stabbed to death outside his home.
Mr Durao died in hospital after being stabbed near his home
The teenager was arrested on Sunday by police investigating the death of Benjamin Durao, 35, in Brixton last month, Scotland Yard said.
Two boys aged 14 and 16 and a man, 24, were previously arrested and bailed in connection with the inquiry.
A 14-year-old has been charged with making threats to kill and blackmail.
Angolan national Mr Durao was attacked on the Myatts Field Estate in Brixton, south London, on 17 December.
He had chased a group of boys who returned to his home after damaging his front door hours earlier.
He later died in a south London hospital.