A woman was left unconscious in the street by robbers who lifted her off the ground by her throat in Notting Hill earlier this year.
The vicious attack happened in broad daylight in Colville Mews at around 3.30pm on Wednesday February 17.
Police released CCTV images on Monday (September 5) of two suspects in the robbery and have asked anyone with information to come forward.
Detective Constable Chris Anderson from the Westminster Crime Squad said: “This was a violent attack on a lone woman in broad daylight. These men left a woman lying on the ground, and all for the sake of £250 ring.
“It is important that they are caught before they hurt anyone else. I would appeal to anyone who recognises either suspect to contact police.”
During the robbery, one man grabbed the victim by her throat and lifted her off the ground, while a second man stole her ring.
The two men ran from the scene towards Lonsdale Road, leaving the woman unconscious on the ground, and they were seen getting into a red Nissan Quashqai and driving away.
Both men were describe as black and both wearing dark coloured clothing.
The first man was wearing a dark hooded gilet, a black baseball cap, dark coloured trousers, trainers and gloves.
He was also carrying a black satchel.
The second man was wearing a dark hooded top, a black woollen hat, tracksuit trousers, trainers and gloves.
Det Con Anderson added: “At this stage we are investigating whether this robbery is linked to similar offences that have taken place in Westminster and Kensington and Chelsea . Any piece of information, however small, may help us to catch them.”
Detectives would also like to hear from anyone who was offered a ring for sale in the days after the robbery.
The ring is described as a silver band with a clear stone, which the suspects may have mistaken for a diamond.
Anyone with information is asked to call police on 101 or anonymously through Crimestoppers on 0800 555 111.