A cyclist had his bike stolen while receiving CPR following an assault.
The 43-year-old man was attacked along a footpath behind Penarth Leisure Centre, Cogan, on August 9 at around 15:30 BST.
However his mountain bike was then snatched by an unknown man while a passer-by performed life-saving treatment at the scene.
A 15-year-old boy from Penarth was arrested on suspicion of assault and released under investigation.
The victim, also from Penarth, remains in a critical but stable condition in hospital following the assault at around 15:30 BST.
Police are appealing for help finding the black and white men's Giant Revel bike.
"His family would like to recover the bike which was the injured man's pride and joy," said police.