Police are investigating the death of Russell Peachey, 35, who was found in Grangetown at about 04:20 BST on Saturday.
They are now searching for James Mark Williams, 31, from Barry in connection with his death.
A 37-year-old man from Barry became the third man to be arrested in connection with the murder on Monday.
All three remain in custody.
Police are searching for a man from the Vale of Glamorgan in connection with a Cardiff murder probe.