A Rolex watch worth around £15,000 was stolen from a man as he was walking home from a shop in Barry.
CCTV has been released of a male suspect following an incident near a bus stop close to the rugby club on Merthyr Dyfan Road last month.
Cash was also taken fom the 40 year-old who had been walking home from the Family Shopper store between 7pm and 7.30pm on Friday 28th November.
South Wales Police have described the robbery as "an isolated and unusual incident".
Detective Constable Alan Skinner said: "I would like to reassure the community that we are conducting a thorough investigation. Whilst the CCTV we have sourced is not of the best quality, we believe that somebody who does know the suspect, may recognise him."
The suspect was filmed before the incident running along Morningside Walk from Elizabeth Avenue - atterwards, he was spotted returning up Merthyr Dyfan Road, possibly back onto Morningside Walk.
He is described as tall and slim and was wearing a dark hooded top with a bright white logo on the back, dark jogging bottoms and trainers with a reflective strip around the base.
DC Skinner added: "I believe the suspect would have stood out in the area at this time due to his clothing and demeanour. He was seen on CCTV running to and from where the incident happened."
"We are appealing for anyone with information which might help us identify the suspect and the whereabouts of the stolen watch, estimated to be worth £15,000."
Anyone with information should contact South Wales Police on 101 or via the live web chat, quoting reference no. 2500375490.
Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.

Barry: three men jailed in shoplifting crackdown
Cardiff Bay connects to heat network
Two boys guilty of Kamran Aman murder
Man's body found in Barry Dock
Another successful year for Santa's Cause
Council set to relaunch petitions scheme
Two men questioned after A48 collision
Candlelighting held at Barry chapel
Power tools found in stolen vehicle
Engineering works to hit Christmas trains
Council sets out future housing plans
Joint police and fire control room criticised
Costs rise for new Cowbridge school
St Athan: plans to build 51 new council homes
Vale Council to continue tax premiums
Penarth: work to make cliff safe after landslips
Debate over single Welsh police force reignited
New five-year food strategy launched