A £20,000 reward is being offered to encourage people to come forward with information about a "very violent individual" involved in an attack which resulted in a heavily pregnant woman losing her baby.
Malorie Bantala, 21, was eight months' pregnant when she was attacked by two men wearing motorcycle helmets in Talfourd Place, Peckham, in south east London in June.
A 20-year-old man, who has been identified by Miss Bantala as the father of her unborn child, has been charged with child destruction and grievous bodily harm with intent.
A provisional trial date for Kevin Wilson, of Longfield Estate, Bermondsey, south east London has been set for November 30.
Detective Inspector David Suddick, from the Met's Homicide and Major Crime Command, today urged anyone with information on a second suspect to come forward.
He said: "The victim has recovered physically from her ordeal but naturally remains devastated at the loss of her baby.
"Somewhere out there is a very violent individual and we hope the offer of this reward may encourage someone to come forward. If you have any information, please contact us."
He added that the victim's white iPhone 5s went missing during the attack and is yet to be traced.
Anyone who can help is asked to contact the incident room on 020 8345 3985 or Crimestoppers anonymously on 0800 555 111.