A 38-year-old man arrested on suspicion of murdering Sabina Nessa has been released under investigation as hundreds of mourners prepared to pay their respects at a vigil on Friday.
Two men arrested on suspicion of murder in recent days have now been released pending further investigation, while police are hunting a third man captured on CCTV near where the primary school teacher was killed.
Ms Nessa, 28, had been walking to meet a friend at a pub near her home in Kidbrooke, southeast London, last Friday when she was fatally attacked in nearby Cator Park.
Her body was discovered by a member of the public the next day, having been hidden under a pile of leaves.
The Metropolitan Police issued footage and images of the man they wish to speak to, which shows him walking in Pegler Square on the evening Ms Nessa was attacked.
A 12-second clip shows a balding man wearing a black hooded coat and grey jeans, holding an orange object, looking over his shoulder and pulling at his hood as he walks down a path.
Detectives have also released an image, captured in the same area, of a silver car they believe the man has access to and appealed for anyone who recognised either to contact the force immediately.
Metropolitan Police Assistant Commissioner Louisa Rolfe urged anyone who may know the man to contact them.
Detective Chief Inspector Neil John, from the Met’s Specialist Crime Command, said “an extensive trawl” of CCTV in the area continued and said information on the man’s identity and whereabouts could be “vital” to the investigation.