A fifth person has been arrested in connection with the murder of a teenager in east London.
A post-mortem exam on Biendi Litambola proved inconclusive
Officers found Biendi Litambola, 17, on Munday Street in Canning Town at just after 1000 GMT on Saturday.
Detectives believe the student, also known as Bobby, from Ilford, east London, had been assaulted.
A 21-year-old man was arrested on Monday. A 22-year-old man remains in custody and three teenagers have been released without charge.
A post-mortem examination has proved inconclusive and police said they were keeping an open mind about the motive.
Biendi's brother, Sammy, said: "I'll miss a big part of me, probably one of the biggest parts of my life. I can't remember him not ever being there.
"It can't be believed, 17 years old. I can't believe that he's gone, I can't believe that it's Bob that has gone."
He added: "Most of the teenagers killed this year are black and most of it is black on black crime. How can we explain this? It's not the police doing it, it's not other races doing it, we are doing it to ourselves. We need to stamp it out."
Biendi is the 24th teenager to be murdered in London in 2007.