A man was knocked to the ground by three robbers near Wakefield Prison on Saturday morning.
The 29-year-old victim was followed and attacked on Marlborough Street as he walked home after a night out in Wakefield city centre
The group assaulted him at around 3am on June 29 and then ran off with his wallet and an amount of cash.
The victim was left with facial injuries. He was treated and later discharged from Pinderfields Hospital.
Wakefield CID would like to speak to anyone with information.
The suspects were described as three Afro Caribbean men. Police would like to speak to anyone who saw three men fitting this description, following the victim from the town centre, past the prison, and on to Marlborough Street.
Anyone with information should call Det Con Neil Whitaker at Wood Street CID on 101 or Crimestoppers anonymously on 0800 555 111.