A 38-year-old man has been arrested on suspicion of the murder of Sabina Nessa in south-east London, the Metropolitan Police said.
Ms Nessa’s body was found by a member of the public in Cator Park in Kidbrooke.
Officers believe the 28-year-old teacher was attacked shortly after leaving her home in Astell Road at about 20:30 BST on Friday.
The force has also released an image of another man they are searching for.
The image shows a figure of a person walking through nearby Pegler Square.
An image of a silver car it is believed he had access to – and that police are searching for – has also been released.
The arrested man was held at an address in Lewisham and remains in custody.
Police said a post-mortem examination carried out on Monday was inconclusive.
Another man in his 40s who was held on suspicion of murder the day after Ms Nessa’s body was found was later released under further investigation.
Ms Nessa was attacked as she walked to meet a friend at The Depot bar at about 20:30 BST last Friday.
Her body was found the next day near a walkway in the park.
Speaking about the CCTV image appeal, Det Ch Insp Neil John said: “We would ask anyone – especially those in Kidbrooke and the wider area of Lewisham and Greenwich – to take a careful look at these images to check whether you know who this man is or have seen him over recent days.
“Any information as to his identity or whereabouts could be vital for our investigation so we are asking you to share this image far and wide to ensure as many people as possible see it.”
Ms Nessa’s family previously said they had been left “devastated” by her killing.
Her cousin, Zubel Ahmed, described the 28-year-old as the “kindest, sweetest girl you could meet”.
He said: “Sabina’s heart was as good as gold, she never had a bad word to say about anyone. Her sister is going to miss her so much.”
Ms Nessa was a teacher at Rushey Green primary school in Lewisham. The head, Lisa Williams, called her “a brilliant teacher; she was kind, caring and absolutely dedicated to her pupils”.
A vigil is due to be held in Ms Nessa’s memory on Friday evening.
It has been organised by a Kidbrooke community group with the support of Reclaim the Streets, which held a vigil for murder victim Sarah Everard in Clapham Common that ended in mass arrests.
Police said they would be part of the gathering.
Source: (BBC news)